Industrial Relations Commission New South Wales

• Medium Neutral Citation: Inspector Nathan Hamilton v Pells Sullivan Meynink Pty Ltd [2012] NSWIRComm 2
• Hearing dates: 25/10/2011
• Decision date: 17 February 2012
• Jurisdiction: Industrial Court of NSW
• Before: Backman J

Decision

1. In Application for Order IRC 1991 of 2007, the defendant is found guilty of the offence and convicted.

2. In Application for Order IRC 1992 of 2007, the defendant is found guilty of the offence and convicted.

3. Both matters are set down for a directions hearing at 10am on Friday, 24 February 2012 for the purpose of setting dates for sentence hearings.

• Catchwords: EX PARTE HEARINGS - Occupational Health and Safety - Occupational Health and Safety Act 2000 (the Act) - two charges against defendant under s 8(1) and s 8(2) of the Act - s 8(1) and s 8(2) charges: Pells Sullivan Meynink (PSM) was an employer - s 8(1) charge: there was a risk to the employees' health, safety and welfare - s 8(2) charge: non-employees exposed to risks to their safety - s 8(1) charge: the risk was to employees at work - s 8(2) charge: PSM's undertaking - s 8(2) charge: the exposure to risk was at PSM's place of work - ss 8(1) and 8(2): a causal nexus between PSM's breach and the risk to employees' safety/the risk arose from the conduct of PSM's undertaking - PSM's responsibilities - what was the design intent/construction sequence developed for the intersection area - non-compliance with design intent and construction sequence by Thiess John Holland (TJH) - Particular c of s 8(1) charge/Particular d of s 8(2) charge: whether failure to implement and maintain adequate system of communication or liaison between PSM and TJH - Particular d of s 8(1) charge/Particular e of s 8(2) charge: whether failure to implement and maintain adequate system of communications or liaison between PSM and Parsons Brinckerhoff (Australia) Pty Limited (PB) - Particular e of s 8(1) charge/ Particular f of s 8(2) charge: PSM failed to prevent its employees/adequately advise that workers should be prevented from performing work in the down drive of the MCAA including its intersection with MC5B - Orders
• Legislation Cited: Occupational Health and Safety Act 2000
• Cases Cited: Inspector Hamilton v John Holland Pty Ltd [2010] NSWIRComm 72; (2010) 194 IR 189
• Category: Principal judgment
• Parties: Inspector Nathan Hamilton (Prosecutor); Pells Sullivan Meynink Pty Ltd (Defendant)
• Representation: Mr J Agius, SC with Mr R Reitano of counsel and Mr B Docking of counsel (Prosecutor); No appearance (Defendant); WorkCover Authority of New South Wales (Prosecutor)
• File Number(s): IRC 1991 of 2007; IRC 1992 of 2007

Judgment

Introduction

1 The defendant, Pells Sullivan Meynink Pty Ltd (PSM) is charged with two offences under s 8(1) and s 8(2) of the Occupational Health and Safety Act 2000 (the Act). Both charges concern the collapse of a large section of tunnel roof on 2 November 2005 during the construction of the Lane Cove Tunnel.

2 On 16 August 2010, PSM wrote to WorkCover Authority of New South Wales informing it of its intention not to take any further part in the present proceedings. Accordingly, the matters proceeded to hearing ex parte.

The Charges

3 The charge under s 8(1) of the Act alleges that PSM, "from about 27 October 2005 to and including 2 November, 2005", was an employer and, "failed to ensure the health, safety and welfare of all its employees, in particular, Daryl Gilchrist", in an area of the tunnel identified in the charge as, "the MCAA including its intersection with MC5B". The risk to safety is identified in the charge as, "... a risk of being struck by falling rock and/or tunnel collapse".

4 The remaining particulars of the s 8(1) charge are set out below:

b) The defendant provided to the Lane Cove Tunnel project during construction:

i. Construction geotechnical services.

ii. As a consultant and an independent contractor, the Senior Rock Mechanics Engineer and Associated Services.

iii. Geologists who undertook geological mapping of the underground excavations and made daily "ground classification & ground support determination".

iv. Core support provided by the defendant's Robert Bertuzzi, Phillip Pells and the defendant's office so that any issues or areas that required further backup were to be handled.

c) The defendant failed to implement and maintain an adequate system of communication or liaison, or both, between the Lane Cove Tunnel's constructor, Thiess John Holland Joint Venture, and the defendant in respect of:

i. The defendant failed to provide any adequate notice to the Lane Cove Tunnel constructor, Thiess John Holland Joint Venture, of the constructor's non compliance with design intent as reflected in the design drawings or construction sequence, or both, and further of the potential risk of rock fall or tunnel collapse, or both, as a consequence of that non compliance.

ii. The defendant failed to provide any adequate notice to the Lane Cove Tunnel constructor, Thiess John Holland Joint Venture, to obtain a new design and construction sequence for the construction of the down drive of the MCAA including its intersection with MC5B in circumstances where the design and construction sequence that had been provided was not followed.

iii. The defendant failed to adequately analyse tunnel mapping and compare that to conditions described in design reports to ensure that support regimes nominated were appropriate and efficient, in that the task was only done weekly and generally on Friday by the Senior Rock Mechanics Engineer.

iv. The defendant failed to adequately liaise with the construction engineers and supervisors regarding the design requirements of the intersection, in that the Senior Rock Mechanics Engineer or geologist only informed them where monitoring installations needed to be installed.

v. The defendant failed to adequately review mapping, ground classification and support types recommended by geologists.

d) The defendant failed to implement and maintain an adequate system of communication or liaison, or both, between the tunnel's designers, Parsons Brinkerhoff Australia Pty Ltd, and the defendant in respect of:

i. The defendant failed to provide any adequate notice to the tunnel's designers, Parsons Brinkerhoff Australia Pty Ltd, of the constructor's non compliance with design intent as reflected in the design drawings or construction sequence, or both, and further of the potential risk of rock fall or tunnel collapse, or both, as a consequence of that non compliance.

ii. The defendant failed to provide any adequate notice to the tunnel's designers, Parsons Brinkerhoff Australia Pty Ltd, that it should provide to the constructor a new design and construction sequence for the construction of the down drive of the MCAA including its intersection with MC5B in circumstances where the design and construction sequence that had been provided was not followed.

iii. The defendant failed to adequately inform the designers that the construction of the down drive of the MCAA and its intersection with MC5B involved benching.

iv. The defendant failed to adequately inform the designers that shotcrete was not being installed in a timely manner thick enough on the walls or from floor to floor over the entire arch, or both.

v. The defendant failed to adequately liaise with the project designers to facilitate changes to the design to tailor it to conditions experienced based on the performance of previously installed support, namely, the rock bolts in the as encountered ground conditions.

e) The defendant failed to prevent its employees from performing work in the down drive of the MCAA including its intersection with MC5B.

5 The charge under s 8(2) alleges that PSM, "from about 27 October 2005 and including 2 November 2005", was an employer, and,

failed to ensure that persons other than its employees, and in particular, John Labruyere, Noel Makene, Mark Watson, Bryan Greenfield, Craig Lightfoot, Steven Swain, Glynn Barker, Lawrence Grace, Chris McKervey, Hamish Studholm, John Wilson, Sam Jones, David Shaw, Regan Findlay, Jason Tyler, Phil Lloyd, Anna Sayyadi, Laura McWinnie, Robert Colquhon, Karen Colquhon, Sylvia Youngeryan and Carlos Baccan were not exposed to risks to their health or safety arising from the conduct of the defendant's undertaking while they were at the defendant's place of work.

6 The failure to ensure the safety of the nominated non-employees of PSM is alleged to have occurred, "in the MCAA including its intersection with MC5B of the Lane Cove Tunnel at Sydney in the State of New South Wales and 11-13 Longueville Road, Lane Cove in the State of New South Wales ("the unit block")".

7 Two risks to safety are identified in the s 8(2) charge, namely, "a risk of being struck by falling rock and/or tunnel collapse", and, "... a risk of subsidence and damage of the ground surface resulting in the undermining of the unit block".

8 PSM's undertaking under the s 8(2) charge is formulated in the charge in the following way:

c) The defendant provided to the Lane Cove Tunnel project during construction:

i. Construction geotechnical services.

ii. As a consultant and an independent contractor, the Senior Rock Mechanics Engineer and Associated Services.

iii. Geologists who undertook geological mapping of the underground excavations and made daily "ground classification & ground support determination".

iv. Core support provided by the defendant's Robert Bertuzzi, Phillip Pells and the defendant's office so that any issues or areas that required further back up were to be handled.

9 The remaining particulars of the s 8(2) charge are set out below:

d) The defendant failed to implement and maintain an adequate system of communication or liaison, or both, between the Lane Cove Tunnel's constructor, Thiess John Holland Joint Venture, and the defendant in respect of:

i. The defendant failed to provide any adequate notice to the Lane Cove Tunnel constructor, Thiess John Holland Joint Venture, of the constructor's non compliance with design intent as reflected in the design drawings or construction sequence, or both, and further of the potential risk of rock fall or tunnel collapse, or both, as a consequence of that non compliance.

ii. The defendant failed to provide any adequate notice to the Lane Cove Tunnel constructor, Thiess John Holland Joint Venture, to obtain a new design and construction sequence for the construction of the down drive of the MCAA including its intersection with MC5B in circumstances where the design and construction sequence that had been provided was not followed.

iii. The defendant failed to adequately analyse tunnel mapping and compare that to conditions described in design reports to ensure that support regimes nominated were appropriate and efficient, in that the task was only done weekly and generally on Friday by the Senior Rock Mechanics Engineer.

iv. The defendant failed to adequately liaise with the construction engineers and supervisors regarding the design requirements of the intersection, in that the Senior Rock Mechanics Engineer or geologist only informed them where monitoring installations needed to be installed.

v. The defendant failed to adequately review mapping, ground classification and support types recommended by geologists.

e) The defendant failed to implement and maintain an adequate system of communication or liaison, or both, between the tunnel's designers, Parsons Brinkerhoff Australia Pty Ltd, and the defendant in respect of:

i. The defendant failed to provide any adequate notice to the tunnel's designers, Parsons Brinkerhoff Australia Pty Ltd, of the constructor's non compliance with design intent as reflected in the design drawings or construction sequence, or both, and further of the potential risk of rock fall or tunnel collapse, or both, as a consequence of that non compliance.

ii. The defendant failed to provide any adequate notice to the tunnel's designers, Parsons Brinkerhoff Australia Pty Ltd, that it should provide to the constructor a new design and construction sequence for the construction of the down drive of the MCAA including its intersection with MC5B in circumstances where the design and construction sequence that had been provided was not followed.

iii. The defendant failed to adequately inform the designers that the construction of the down drive of the MCAA and its intersection with MC5B involved benching.

iv. The defendant failed to adequately inform the designers that shotcrete was not being installed in a timely manner thick enough on the walls or from floor to floor over the entire arch, or both.

v. The defendant failed to adequately liaise with the project designers to facilitate changes to the design to tailor it to conditions experienced based on the performance of previously installed support, namely, the rock bolts in the as encountered ground conditions.

f) The defendant failed to adequately advise that workers should be prevented from performing work in the down drive of the MCAA including its intersection with MC5B.

10 In both charges "MCAA" refers to the Pacific Highway exit ramp tunnel and "MC5B" refers to the Marden Street ventilation tunnel.

Background

11 A document outlining the factual background leading up to the alleged offences was provided to the Court for its assistance. I have cross-referenced the information set out in the document to the prosecution's brief of evidence and am satisfied that it accurately reproduces and otherwise conforms to the evidence contained in the brief. The document has been particularly helpful in providing background material and in clarifying the roles of the various entities involved in the Lane Cove Tunnel project (LCT project). Part of the material in the document (referred to as the Statement of Facts) is extracted below:

2. At all material times Pells Sullivan Meynink Pty Ltd [ACN 061 447 621] ("PSM") was a corporation whose registered office is situated at Blackwood Clarke, Suite 502A, Level 5, 282 Victoria Avenue, Chatswood, in the State of New South Wales ("the defendant") ( tab D20 ).

3. At all material times the defendant was an employer ( tab S24 Clark at Q20; tab S23 Bertuzzi at Q20; tab S26 Gilchrist at Q20). Philip Clark was employed by PSM as the Senior Rock Mechanic Engineer ( tab S26 Clark at Q12-Q14), Daryl Gilchrist was employed as a senior geologist, Robert Bertuzzi was employed as a Principal Engineer ...

4. The Roads and Traffic Authority ("RTA") engaged the Lane Cove Tunnel Company Pty Ltd, now known as Connector Motorways Pty Ltd, to design, construct, maintain and operate the Lane Cove Tunnel (LCT). The LCT and associated works were being constructed to link the M2 Motorway with the Gore Hill Freeway ( tab D1 ).

5. The Lane Cove Tunnel Company Pty Ltd contracted Thiess John Holland Joint Venture to design and construct the tunnel and associated works. The construction of the LCT commenced in 2004 ( tab D1 ).

6. The co signatories of the Thiess John Holland Joint Venture ("TJH") were Thiess Pty Ltd and John Holland Pty Ltd ( tab D1 ).

7. TJH engaged Parsons Brinckerhoff Australia Pty Ltd ("PB"), design consultants to design the project ( tab D2 ).

8. PSM, a company involved in design consultancy and supply of construction phase services such as geological inspection/mapping and monitoring, provided geologists and geotechnical staff to assist both PB in the design stage and TJH and PB in the construction phase. Staff worked with these two organisations at different stages of the project ( tab D3, D6, D7, D8 ).

9. In October 2004, TJH engaged PSM to provide a Senior Rock Mechanics Engineer and associated services (the "PSM Rock Mechanics Engineer Consultancy Agreement").

10. As at October 2004 and at all times subsequently, PSM was a specialist geological consultant with world renowned experience in geological conditions in the Sydney basin.

11. Under the PSM Rock Mechanics Engineer Consultancy Agreement, PSM was to provide the services of a specialist Rock Mechanics Engineer to overview the construction of the LCT and associated works with regard to the following points:

Interpret data received from tunnel and surface mounted ground monitoring instrumentation.

Analyse tunnel mapping by a geologist and compare that mapping to conditions described in design reports to ensure that support regimes nominated were appropriate and efficient.

Liaise with the Project designers to facilitate changes to the design to tailor it to conditions experienced based on the results of instrumentation and performance of previously installed support.

Liaise with construction engineers and supervisors regarding the design requirements.

Manage TJH's monitoring activities (specified by others) connected with the Project.

Co-ordinate geologists and engineers seconded to the monitoring team by PB, Coffey Geosciences and PSM.

Ensure that adequate records of monitoring activities were kept in an agreed format for use and consultation by TJH staff and designers.

Co-ordinate the TJH survey teams inputs into the monitoring activities.

Manage and co-ordinate the installation of monitoring equipment whether installed by TJH or subcontractors.

Provide geotechnical technicians to read all instruments installed as part of the construction of the works.

12. Under the PSM Rocks Mechanics Engineer Consultancy Agreement, PSM was obliged to exercise all the skill, care and diligence of a professional consultant experienced in providing the services and was obliged to carry out all responsibility in a thorough, skilful and professional manner ( tab D6 & D7 ).

13. URS Australia Pty Ltd ("URS") were appointed by the RTA as the Independent Verifier for the project.

14. In the period 27 October 2005 to 2 November 2005 the following people worked in the MCAA including in its intersection with MC5B: Laurence Grace ( tab S3 at Q60), Glynn Baker ( tab S1 ), Dave Shaw ( tab S8 at Q40-41), Stephen Swan ( tab S10 at Q36-37), John Labruyere ( tab S5 at Q33-37), Regan Findlay ( tab S2 at Q30-42), Craig Lightfoot ( tab S6 at Q51), Bryan Greenfield ( tab S4 at Q41-48), Jason Tyler ( tab S13 at Q29), Hamish Studholme ( tab S9 at Q31), Noel Makene ( tab S7 at Q30-37), Mark Watson ( tab S11 at Q29-36), Christopher McKervey ( tab S12 at Q32-34), John Wilson ( tab S16 at Q45), Sam Jones ( tab S14 at Q66), Phil Lloyd ( tab S20 at Q40, Q60).

15. In the period 27 October 2005 to 2 November 2005 the following people lived in the home units located at 11-13 Longueville Road, Lane Cove which was above the area where the incident occurred: Anna Sayyadi ( tab S30 ), Laura McWhinnie ( tab S31 ), Robert Colquhoun ( tab S29 ) and Carlos Baccan ( tab S28 ).

Incident

16. On Wednesday, 2 November 2005 TJH employees were carrying out excavation works at the junction of two tunnels, the Marden Street ventilation tunnel and the Pacific Highway exit ramp. At approximately 1:40am a large section of the tunnel roof collapsed in the area underneath the Longueville Road off-ramp to the Pacific Highway at Lane Cove. The employees working within the tunnel evacuated the tunnel as the section of tunnel roof collapsed narrowly escaping injury ( tab S5 John Labruyere at Q33-36; tab S4 Craig Greenfield at Q41-48; tab S7 Noel Makene at Q30-37).

17. The collapse led to a significant ground subsidence that affected the stability of a block of home units situated at 11-13 Longueville Road, Lane Cove. There were also concerns relating to a retaining wall that supported the Pacific Highway off-ramp. The incident caused the off-ramp and Longueville Road to be closed and residents of the home units to be evacuated (see the residents' statements at tab S28 to S31 ).

The Occurrence

18. The incident occurred at the junction of two tunnels: the Marden Street ventilation tunnel (referred to as MC5B) and the Pacific Highway exit ramp excavation (referred to as MCAA) (see, for example, tab S5 Labruyere at Q33). Over the previous weeks MC5B had been advancing towards the line of MCAA and reached the intersection point with MCAA around 17 October 2005 ( tab D10 & tab D12 ). Once this point was reached MCAA was excavated first to the east (referred to as the "up" or "upper" drive), and then to the west (referred to as the "back", "lower" or "down" drive). Work was continuing on this western excavation at the time of the collapse ( tab D12 ).

19. On the evening prior to the incident, 1 November 2005, the night tunnelling crew ("crew B") commenced their shift at 1900 hrs. The crew was comprised of four workers: John Labruyere, the leading hand, Noel Makene, the road header operator, Bryan Greenfield, the loader operator and Mark Watson, the driver of the dump truck. The crew were all employed by TJH (see Tab S4 Greenfield, tab S5 Labruyere, tab S7 Makene and tab S11 Watson).

20. The crew on the preceding day shift ("crew A"), according to shift reports, had installed and grouted five rock bolts on the MCAA down left, installed but not grouted five rock bolts on the MCAA down left, installed and grouted 2 rock bolts on the MCAA down right, and had installed some shotcrete (see tab D12 ). The shift report for this shift does not indicate what chainage the excavation of the lower drive of MCAA was at the conclusion of the day shift. Ground Support Classification and Ground support determination reports indicate that the down drive of the MCAA was at chainage 467 when inspected near the start of the day shift (see tab D10 ). Crew A consisted of Craig Lightfoot, Steve Swain, Glynn Barker and Lawrence Grace.

21. Crew B on the night shift on 1 November 2005/2 November 2005 had cut approximately one metre into the left side of MCAA down drive and had commenced loading out and "mucking out" spillage from the front of the road header when, at about 1:40 am, the rock collapse commenced. Mr Labruyere, described what happened:

I was standing on top of the road header next to the operators cab talking to the operator ... We were just doing a bit of mucking out waiting for the shotcreters, ...and I noticed the whole roof, from the centre to right side of MCAA coming down as a whole mass and back towards us, and we were out of there. I can't remember from that point, when we turned around there was stuff falling on our lid and from that point I have a gap in my memory until I reached the truck. One comment from the truck driver was he heard a banging and crashing and got out of his cab, and saw the road header cab was almost completely covered ( tab S5 Labruyere, Q36).

22. Once the fall commenced, it increased rapidly when it reached an area where a dolerite dyke was situated. The crew, under instructions from the leading hand, retreated from the area, back to the entrance of MC5B, which was then secured (taped off).

23. The acting shift boss, Craig Bennett, who was operating with another crew in tunnel MC1A East, was then notified of the incident and travelled to the scene of the collapse with the leading hand of crew B. After observing that the area was still unstable, the evacuation alarm was activated and all tunnels in the Marden Street area were evacuated (see tab S17 Bennett).

24. At approximately 2:00am, a hole was observed off the exit ramp in front of the "Kerslake" apartment block (11-13 Longueville Road). It also appeared that the subsidence had fractured a water pipe, causing a substantial inrush of water into the collapse.

25. Once the tunnels were evacuated and all workers accounted for, management representatives, geologists and engineers were progressively contacted and requested to attend the site. Subsequently, inspections were carried out both underground at the scene of the collapse and on the surface. At approximately 2.30am the hole was observed to be about 4 or 5m diameter on the surface and had undermined approximately 1-2m under the road.

26. Staff considered that the collapsed debris required strengthening before any surface activity could occur. It was proposed to place large diameter hammered rock to form a bridging layer to lessen any pressure on the pile of collapsed debris. However, they needed to remove an electrical sub-station and a dust scrubber from the area before the rock could be placed up against the debris pile delayed this action. This strategy was discarded as observation of the hole at approximately 5:30am revealed the hole had expanded in size. At about 6:00am loud noises were heard to be coming from the hole and it was observed that a substantial secondary collapse had occurred under the existing Longueville Rd exit ramp and a number of piles with the collapsed area of the tunnel were observed to have been undermined by the collapse. The hole at that stage was observed to be around 8-9m diameter.

27. It was at this stage that the decision was made by TJH to commence filling the hole with concrete to mitigate any further collapse. Concrete pumping commenced with one pump at approximately 8am. Two further concrete pumps arrived shortly after and also commenced pouring, the initial pour ceasing at around 3:00pm, having reached a height of 2 metres above the top of the pile. This amount of concrete had been determined as the maximum that could be placed initially without putting pressure on the exit ramp retaining wall. Longueville Road had been closed to traffic at approximately 6:45am.

28. After waiting for the first lot of concrete to cure a second pour was commenced at approximately 9:30pm on 2 November 2005 and completed at around 12:30am the following morning. The third and final concrete pour, which was to reach the level of the top of the retaining wall, was commenced at 6:30am on 3 November 2005 and completed mid-morning. Over the next couple of days, grout was pumped into identified void areas around the collapse to complete the stabilisation works. In total, approximately 2750 cubic metres of concrete and grout was pumped into the collapsed area (see tab D21 and tab D14 Golder report pages 19-22 for further detail of the incident).

Geological Conditions at the Site

Low Strength Shale

29. The bedrock at the site consisted of Ashfield Shale. In the area of the MC5B/MCAA intersection, the bedrock in the crown of the tunnel had been documented by the Project Geologist as Ground Class LCTG7 and LCTG8, that is, shale of low to very low strength (see tab D10 , GSD dated 1 November 2005, see tab S20 Lloyd at Q37). Previous investigations and assessments in the area had also indicated that the strength of the shale further decreased closer to the ground surface, in turn passing up to residual soil and/or some overlying fill. This material thus comprised a low strength sequence, from the crown of the tunnel up to the surface infrastructure (see tab D15 Kotze report at page 11).

The Presence of the Dyke

30. The MC5B/MCAA intersection was transected in a southeast to northwest direction by an igneous (doleritic) dyke. The dyke comprised a subvertical, through-going intrusion, generally ranging in true thickness from between 600 and 700mm. Dyke intersections had been encountered previously in MC5B as well as in the main line tunnels and the occurrence of the dyke in or near the MC5B/MCAA intersection was anticipated by site personnel ( tab S26 Gilchrist at Q112-116, tab D15 Kotze report at page 11).

31. In previous encounters the dyke was predominantly orange in colour, highly to extremely weathered and of low to very low strength. These conditions are understood to have prevailed through the MC5B/MCAA intersection. The dyke comprises a persistent low strength feature, both laterally and vertically, and its side boundaries constitute low strength defect planes (see tab D15 Kotze report at page 11).

Rock Mass Joints and Faults

32. Mapping documentation completed by the Project Geologist confirmed that the rock mass into which the MC5B/MCAA intersection had been excavated was relatively highly fractured. The shale in this area was characterised by structures comprising bedding plane partings, joint plane defects and localised faults (see tab D15 Kotze report at page 11).

33. Bedding plane partings are subhorizontal to locally dipping defects of variable vertical spacing. They are intersected by inclined to subvertical joint plane fractures. Mapping confirmed the presence of three (3) intersecting joint plane sets, one of which was parallel to the dyke, whilst the other two were both normal and more acutely angled to it. These subvertical fracture sets are locally continuous upwards and spaced as closely as 200 mm apart. They effectively divide the rock mass into a series of vertical columns, which can in turn be subdivided into blocks by intersecting with sub horizontal bedding planes (see tab D15 Kotze report at page 11 & 12).

34. The rock mass in the MC5B/MCAA intersection was further fractured by localised inclined fault structures that were mapped by the Project Geologist. In combination with the bedding plan partings and joint plane fractures described above, the localised faults further fragmented the rock mass into variously shaped and sized blocks and wedges (see tab D15 Kotze report at page 12).

Large Span Width of Tunnel Intersection

35. Both the ventilation tunnel (MC5B) and the Pacific Highway Exit Ramp (MCAA) were "Two Lane" tunnels within the Lane Cove Tunnel Project, with spans or widths of approximately 9 metres. At the intersection of the two tunnels however, the width of the underground opening was locally greater. The diagonal width of the MC5B/MCAA intersection was up to 22m (see tab D15 Kotze report at page 7). This is a relatively large effective span width to support, particularly when the roof strata were comprised of low strength and fractured shale. Furthermore, the above described weathered and low strength dyke passed through the intersection as a zone of weakness, aligned closely with the line of maximum span (see tab D15 Kotze report at page 12).

Tunnel Roof Support Installations

36. The roof support adopted at any tunnel location on the project was dependant on the assessed "Ground Classification", which in turn related to a "Ground Support Determination". As mentioned above the assessed ground classes in the area of the MC5B/MCAA intersection were LCTG7, LCTG7/G8 and LCTG8. Early project documents relate a ground class of LCTG7 (for a 2 lane/9m tunnel width) to a support system comprising an array of 3m long rock bolts on a 1250mm spacing both ways, with an initial 50mm lining of shotcrete and a second/final 75mm lining of shotcrete. Ground class LCTG8 required Steel Sets or Lattice Girders, with an initial 75mm lining of shotcrete and a final 200 mm lining (see tab D15 Kotze report at page 7 & 8).

37. The amount of rock bolts to be installed and the thickness of the shotcrete varies depending on the ground support determination ("GSD") (based on the ground classification determined by the geologist) in the design documents. If the "as found" conditions vary significantly from what was expected, a "Request Further Information" form was referred back to the tunnel designers who would consider the new information and, if required, issue a revised set of drawings. Any design revisions would be submitted to the independent verifier for approval.

38. As the project advanced and poor ground conditions associated with low strength fractured shale and dyke intersections were encountered, the LCTG7 ground support system was upgraded to 4m long rock bolts on 1000mm x 1250mm spacings with two (2) cyclic 100mm applications of shotcrete (Mar VII Support Type). The original LCTG8 requirement for Steel Sets or Lattice Girders in poorer ground conditions however, was also modified, to a less conservative rock bolt and shotcrete application (see tab D15 Kotze report page 8).

39. When the doleritic dyke was encountered in the MC5B drive in September 2005, geological predictions were that it would be encountered again in the vicinity of the intersection of MC5B and MCAA and a revised drawing for the intersection was issued. This new design was not verified by URS prior to it being adopted for construction ( tab S26 Gilchrist at Q76).

40. In the area of the MC5B/MCAA intersection, a modified Mar VII 4m rock bolt and shotcrete support type was employed, with a supplementary 5m long rock bolt pattern in the centre of the intersection including the southern and eastern transitions. Shotcrete was to be applied in two layers of 100mm. One layer prior to bolting and the second layer to be sprayed after the bolts had been installed. The shotcrete was to form a complete arch from floor to floor ( tab S26 Gilchrist at Q69-70) (see tab D15 Kotze report page 8).

41. Beyond the transition zones, the modified Mar VII support type only was installed, that is, without the supplementary 5m rock bolts. It is understood that the MCAA up drive should have been installed with 4m long rock bolts on a 1m x 1m grid pattern, with two shotcrete applications comprising a 125mm thickness. It is understood that the MCAA down drive had been partially installed (on the northern side) with 4 m long rock bolts on a 1m x 1m grid pattern, with an initial application of shotcrete of unknown thickness (see tab D15 Kotze report page 8).

42. Instructions and information about the method of excavation work to be carried out on the LCT project were provided to the crew by induction into Job Safety and Environment Analyses ("JSEA"). These JSEA included procedures for road header excavation, loader operation, dump truck operation, rock bolting, ventilation and the use of compressed air equipment. Directions on the sequence of construction in particular areas were issued in the form of site instructions that were communicated to the crews by the shift boss and/or leading hand. The site instructions were then usually affixed in the cabin of the road header.

43. The site instruction issued for the construction sequence in the intersection of MC5B and MCAA required the crew to cut a prescribed minimum distance (about 1-1.5m) and stop. The road header would then be pulled back and the newly excavated area shotcreted. The crew would then leave the shotcrete for approximately an hour for it to cure, and then install an amount of rock bolts as determined by the design documents. This process involves drilling a hole, inserting and tensioning the bolts and finally pumping in grout to complete the installation. The support was to be installed to the full face of the advancing tunnel. Full implementation of the design was considered essential for it to be effective. The shotcrete role is significantly greater given the poor geological conditions as under those conditions the shotcrete can be expected to be directly loaded by the shale and is required to perform as a structural shell. The sequence of application of the shotcrete and the completion of shotcrete in accordance with the design becomes of more significance than in more favourable ground conditions (see tab D9 and tab D15 Kotze report page 18).

Ground support determination and monitoring

44. Although this support regime was generally considered to be robust by the design team, it was considered necessary to draw the constructor's attention to the need to have a geotechnical engineer monitor the "as found" ground conditions as construction progressed as the design may need to be reviewed or adapted. The geotechnical engineer and/or the geologist was also to direct the installation of spot bolts in the tunnel walls should that be considered necessary.

45. The system of ground mapping and ground support determination is defined in TJH Work Method Statement Geotechnical Mapping and Ground Support Determination No TJH-WMS-TU-CON-016 ( tab D5 ). Essentially the procedure for ground mapping and support determination was that a Geologist, Daryl Gilchrist (PSM) would attend, inspect and map the face of tunnels under construction, and produced a Ground Support Determination Sheet (GSD) ( tab S26 Gilchrist at Q132-137). On occasion and if needed he would consult with the Geotechnical Engineer, Phil Lloyd (PB's Design Representative) who often attended the face, on the ground support determination (GSD's) made. Daryl Gilchrist would then provide the GSD to the TJH Senior Engineer, Sam Jones for confirmation. Sam Jones would then distribute the GSD information and recommendations to the superintendent and shift bosses for implementation. The responsibility for ensuring the procedure was carried out in accordance with the guidelines was delegated down the line by the Construction Manager Tunnels (Steve Wille) to the Project Manager (Duncan Shires) down to the Senior Project Engineer (Sam Jones) and Superintendent (John Wilson).

Section 8(1) charge: elements

12 The elements of the charge under s 8(1) which the prosecution is required to prove beyond reasonable doubt are:

1. PSM was an employer at the time of the alleged breach.

2. There was a risk to the employees' health, safety or welfare.

3. There was a causal nexus between PSM's alleged breach and the risk to the employees' health, safety or welfare.

4. The risk was to the employees at work: see also Inspector Hamilton v John Holland Pty Ltd [2010] NSWIRComm 72; (2010) 194 IR 189 ( John Holland ) at [103].

13 The elements of the charge under s 8(2) which the prosecution is required to prove beyond reasonable doubt are:

1. PSM was an employer at the time of the alleged breach.

2. There were persons not employees of PSM exposed to risk to their health or safety.

3. The risk arose from the conduct of PSM's undertaking.

4. The exposure to risk was at PSM's place of work: see also John Holland at [104].

Section 8(1) and section 8(2) charges: PSM was an employer

14 As the document partially extracted above demonstrates, PSM, at the time of the alleged breaches, employed Mr Bertuzzi as a principal engineer, Mr Clark as the senior rock mechanic engineer and Mr Gilchrist as a senior geologist. Letters on PSM letterhead contain statements that Mr Bertuzzi was employed by PSM as a principal geotechnical engineer and Mr Clark as a senior engineering geologist. Statements of Mr Bertuzzi and Mr Clark forming part of the brief confirm that both men were employees of PSM during the period of the alleged breaches. A statement by Mr Gilchrist which also forms part of the brief indicates that he was employed by PSM on 2 November 2005. This evidence taken as a whole proves, beyond reasonable doubt, that PSM was an employer during the period of the breaches.

Section 8(1) charge: there was a risk to the employees' health, safety and welfare

15 Mr Gilchrist attended the area of the intersection on two occasions on 1 November 2005. On the first occasion, he mapped the exposed rocks and took a number of photographs. He noted that a "clock-it" hole had not been drilled for the installation of a monitoring device. He returned to the area at about 10am for a second inspection and to install the monitoring device. While there he discussed with Mr Lloyd a number of matters which included the ground conditions, the shape of the tunnel, that is, the fact that the down drive of the MCAA was being "widened out", the rock bolting at the intersection, the condition of the dyke, the spacing of joints and the existence of faults.

16 According to Greg Kotze, a consulting engineering geologist and an expert in engineering geology, rock mechanics, rock mass support and stabilisation, and geological modelling, during the period in which Mr Gilchrist attended the area of the intersection, there was a risk to the health and safety of persons working there because of the risk of roof failure or collapse. In his report dated 12 June 2007, Mr Kotze said that he first attended an inspection of the collapsed site at 6am on 3 November 2005 and conducted investigations. He subsequently attended the site on numerous occasions and carried out geotechnical site inspections, made direct factual observations, compiled photographic records and undertook geotechnical services. This material formed the subject matter of his Report and the basis for his opinions and conclusions. In relation to the risk to employees working in the area during the period of the charge he explained:

Inherent in every underground excavation in rock are the combined effects of subsurface disturbance and gravity, which can cause rock masses to fall from the roof of a tunnel and sections of tunnel roof to collapse, thereby presenting a risk (or potential danger to health and safety) to persons working in the tunnel.

Between 01 August 2005 and 02 November 2005, the excavation of the ventilation tunnel (MC5B) advanced from approximately chainage 68m to chainage 198m and into the intersection with the Pacific Highway exit ramp tunnel (MCAA). This involved an excavation length of around 160 metres, over a three-month period, which is delineated on the attached Figure 1. Project documents (Geological Mapping Sheets, Ground Classification & Ground Support Determinations - References 1 to 64) indicate that the geological and roof stability conditions encountered in MC5B during this excavation period, were generally worse than had been encountered in other tunnels on the project, and also tended to progressively deteriorate towards and into the MC5B/MCAA intersection (as described below). Deteriorating rock mass and stability conditions in the roof of a tunnel excavation corresponds with an increase in risk (or increased potential danger) to persons working in the tunnel.

17 Mr Kotze identified four primary factors which he said combined to cause the roof collapse at the intersection on 2 November 2005. These were:

i) The geological conditions at the site . See References 1 to 21 and Plates 5 to 16. The roof of the MC5B/MCAA intersection is characterised by:

Low to very low strength shale bedrock

A weathered, low strength igneous dyke crossing diagonally through the intersection

Closely spaced rock mass fractures including bedding plane partings, intersecting joint sets, and localised faults. See Figure 2.

ii) The large span width of the MC5B/MCAA intersection . The spans or widths of the MC5B and MCAA tunnels are approximately 9 metres (Figures 5, 6 and 7). The diagonal width of the underground opening comprising the intersection of both tunnels however, is up to 22 metres. See Figure 3. The line of maximum span aligns closely with the low strength igneous dyke that crosses through the intersection.

iii) Proximity of the tunnel excavations to the ground surface . The crown of the MC5B/MCAA intersection is 13.3m below the level of Longueville Road and around 17m below the existing Pacific Highway off-ramp and ground level at the western end of the Kerslake Apartments. See Figure 4. The intersection is also overlain on its southern side by the Longueville Road retaining wall which comprises anchored concrete piles. The tie-back anchors were up to 18m long and angled down at 50  below horizontal, extending to depths in the order of 2m above the crown of the MC5B/MCAA intersection. Each anchor had been installed into a 125mm diameter hole that had been over-drilled by 05m, continuously flushed during drilling, reflushed and water tested, before being grouted. Some twenty eight (28) anchors are believed to have been installed into the low strength shale rock mass above the MC5B/MCAA intersection. (Reference 67).

It is considered likely that the anchor drilling and installation processes would have locally disturbed and weakened the already low strength and fractured shale strata on the northern side of the retaining wall. The MC5B/MCAA intersection was subsequently excavated immediately beneath the wall anchors.

iv) The inadequacy of the tunnel roof support installations . The installed roof support which comprised CT rock bolts and shotcrete, was not capable of supporting the rock mass conditions encountered in and above the roof of the intersection, over the excavated span.

The adopted roof support system relied on the composite effects of a 200mm thickness of shotcrete from floor to floor, and arrays of CT rock bolts. At the time of the roof collapse in the MC5B/MCAA intersection, the application of shotcrete had not achieved full thickness and did not extend from floor to floor. (References 1, 2, 4 and 5). See Plates 12, 14, 15, 17, 18 and 19. Furthermore, and as described in detail herein, evidence from rock bolts recovered from the failure site is considered to indicate that a significant percentage of the CT rock bolts installed, had not achieved end anchorage or a grouted bond in the roof strata. With a deficiency of roof support, in adverse geological conditions, the intersection collapsed when a critical span width was reached.

18 It follows from the matters set out by Mr Kotze in his Report that Mr Gilchrist, an employee of PSM, was at risk to his safety by reason of his presence in the area of the intersection (where the roof collapsed) at least on two occasions on 1 November 2005.

Section 8(2) charge: non-employees exposed to risks to their safety

19 The matters identified in Mr Kotze's Report (set out above) demonstrate a risk of roof or tunnel collapse in the intersection of the two tunnels during the period of the charge, that is, between 27 October 2005 and 2 November 2005. Members of the TJH tunnelling crew reported observations shortly before the roof collapse consistent with deteriorating roof conditions such as persistent rock falls and poor ground conditions.

20 Mr Baker, employed by TJH as a tunneller and truck driver, said that the ground, particularly the lower corner of the MCCA, "had been getting pretty bad", and that there were, "pretty big fallouts of rock". He also said the crew had trouble with the bolts "taking up" and with grouting the bolts because of the cracks in the rock which caused the grout to drip out. Mr Grace, a road tunneller employed by TJH, said that because of the pressure of the dyke in the intersection, they were, "getting a lot of slabby falling rock, and it was very hard to support". He said there was a lot of concern about rock fall and that about four weeks prior to the roof collapse on 2 November 2005, the conditions in the area of the intersection, "started getting really bad". Mr Labruyere's account of the roof collapse on 2 November 2005 has been earlier set out in this judgment. At the time of the roof collapse he was employed by TJH as a leading hand. Mr Shaw, employed by TJH as a road header operator, said he did not feel safe working in the area of the intersection because of his concerns that the rock bolts could not support the soft ground there. Mr Swan, employed by TJH as a shift boss, described the ground in the area as "bad". He said that a week before the roof collapse the crew was using a lot of water to drill holes for inserting 5m rock bolts and the water was coming out "all around us, which shows what the ground is like above". Mr Tyler, a shotcreter employed by TJH, described the ground conditions in the area of the intersection just prior to the roof collapse as, "pretty dodgy", with a few rock falls at the face. He described problems associated with shotcrete adhering to the dyke, saying that after it was sprayed onto the dyke, it "kept on trying to fall off".

21 These accounts, together with Mr Kotze's observations and opinions, demonstrate that a number of workers employed by TJH in the area of the intersection during the period of the charge were exposed to a risk to their safety by reason of a risk of being struck by falling rock and/or tunnel collapse.

22 The second risk to safety, identified in the charge as the risk of subsidence and damage of the ground surface resulting in the undermining of the unit block, concerns residents of the unit block and their experiences in the period prior to and at the time of the roof collapse on 2 November 2005.

23 One of the residents, Mr Baccan, at about 2am on 2 November 2005, described a big hole he saw from his balcony. Shortly after he said he and other residents evacuated the building. Another resident, Mr Colquhoun described a loud noise and saw a big hole which he said, "was expanding by the minute. Bits were falling in". Ms McWhinnie, another resident in the unit block at the time of the roof collapse, described the incident in the following way:

I was awoken by strange noises which was the sound of debris falling in between the walls and under the building.

When I tried to get out of my room, I was trapped. The building had shifted while I was asleep and as a result the door had become jammed. I eventually got out and ran outside. At this stage the hole had not opened up, but there was water spraying from a crack in the road and footpath. A large semi trailer came up the exit ramp to the Pacific Hwy and I tried to flag him down as the crack was across the road. The truck continued to drive through and as it passed part of the road and footpath collapsed.

I ran back into the building and knocked on doors and rang buzzers to wake everyone up. By the time I came back out and ran around to the front of the building the hole was massive. While was waking people, my flatmates boyfriend called the emergency services and it was around this time that they arrived.

When I was trapped in my room I thought I was going to be buried alive as I could hear by flatmate screaming that the walls were cracking and that I needed to get out. I could also hear the debris falling in the walls and the cracking of the walls in my apartment. When I got out of my room I could see that my apartment was cracking at a rapid rate. I felt very scared but was running on adrenalin. When I was waking the residents of the building up, I was literally shaking as I ran back into the building as I thought it could come down at any moment.

24 The Statement of Facts extracted above describes the hole which was observed off the exit ramp in front of the unit block at about 2am on 2 November 2005. The document also refers to subsidence which fractured a water pipe and caused a substantial inrush of water. By 2.30am, the hole had increased in diameter on the surface to about 4-5 metres and had undermined about 1 to 2 metres of the road. The size of the hole continued to expand causing TJH to abandon a strategy to contain the collapse which involved placing rocks to form a bridging layer in order to lessen the pressure on the pile of collapsed debris.

25 These matters clearly demonstrate beyond reasonable doubt that residents of the unit block were placed at risk to their safety by reason of subsidence and damage to the ground surface, affecting the integrity of the unit block as graphically depicted by the residents, in particular, Ms McWhinnie.

Section 8(1) charge: The risk was to employees at work

26 Mr Gilchrist was at work in the area of the intersection during the period of the charge and during the period when he was placed at risk to his health, safety and welfare.

Section 8(2) charge: PSM's undertaking

27 PSM's undertaking is set out in the PSM Rock Mechanics Engineer Consultancy Agreement. Under that agreement, which was entered into between TJH and PSM, PSM was to provide the services of a specialist rock mechanics engineer to overview the construction of the LCT and associated services, as set out in Part A of the Schedule attached to the agreement. Mr Clark was the senior engineering geologist employed by PSM and seconded to the joint venture. He was responsible for carrying out the functions of the specialist rock mechanics engineer outlined under Part A of the Schedule. Those functions, or services, have been extracted in this judgment from the Statement of Facts. Mr Gilchrist, a senior geologist, performed a role in the area of the intersection during the period of the charge consistent with providing critical information in order to facilitate the discharge of PSM's functions set out in Part A of the Schedule.

28 PSM's undertaking is also set out in correspondence between it and PB. According to that correspondence, PB engaged PSM, "to provide technical reports and review during the design phase of the project and further to assist and perform specific tasks as requested by PB". A further document forming part of the evidence set out the roles or functions PSM was required to perform, by TJH, during the construction phase of the LCT. These included the following items:

1. Geologists (3 for the tunnel and 1 for surface works)

a. geological mapping of the underground and surface excavations,

b. updating geological model,

c. maintaining geological records and drawings,

d. prediction of geological conditions ahead of tunnelling and surface excavations,

e. advising tunnelling crews and surface workers on support requirements,

f. confirm piling and anchorage depths,

g. surface and underground instrument monitoring - geotechnical and hydrogeological,

h. updating databases - settlement, inclinometers, extensometers, convergence, groundwater levels, etc.

i. maintaining records and graphs.

It is intended that there be at least one geologist per day available for face mapping, support determination and monitoring, with the possibility of additional staff being allocated where required.

2. Senior Rock Mechanics Engineer

a. interpretation of tunnel and surface geotechnical data (geology and monitoring),

b. analyses of conditions,

c. critique design and construction

d. liaising with designers via the Senior Tunnel Design Engineer and Senior Geotechnical Engineer

e. liaising with TJH Construction

f. manage the geologists, instrumentation suppliers, road traffic controllers, drillers, drilling permits, etc

Note that as Construction is affected by the findings, the Senior Rock Mechanics Engineer should report to Construction directly.

29 The issue concerning whether the risks arose from the conduct of PSM's undertaking will be examined separately.

Section 8(2) charge: the exposure to risk was at PSM's place of work

30 PSM's place of work included the LCT network, in particular, the area of the intersection where the tunnelling crew and other workers (including Mr Gilchrist) were operating during the period of the charge. I have already made findings that these workers were exposed to a risk to their safety by reason of the risk of roof or tunnel collapse in that area. PSM's place of work extended to the adjacent unit block by reason of the area and location of subsidence and damage to the ground surface at the time of the roof collapse which directly affected the integrity of the unit block causing substantial structural damage and exposing the residents there to risk.

Sections 8(1) and 8(2): a causal nexus between PSM's breach and the risk to employees' safety/the risk arose from the conduct of PSM's undertaking

31 Both elements outlined in the sub-heading immediately above involve an examination of the evidence in order to determine whether there exists the requisite nexus, or connection, between PSM's acts or omissions, as particularised in both charges (the alleged failures) and the risks to safety to both employees and non-employees. The particulars of PSM's alleged failures set out in both charges are for the most part substantially similar. Particular c of the s 8(1) charge is identical to Particular d of the s 8(2) charge. Particular d of the s 8(1) charge is identical to Particular e of the s 8(2) charge. Accordingly, it is convenient to consider together each set of identical particulars. Before doing so, it is necessary to establish the following matters:

i) what were PSM's responsibilities with regard to the LCT project;

ii) what was the design intent/construction sequence developed for the construction of the intersection and the down drive of the MCAA;

iii) was there non-compliance by TJH with the design intent and the construction sequence?

PSM's responsibilities

32 PSM's responsibilities by reference to the LCT project have been earlier set out. Those responsibilities included the interpretation of data that was received from the tunnel and analysing tunnel mapping performed by Mr Gilchrist in order to compare the tunnel mapping with what was described in the design reports to ensure that the construction work being carried out in the tunnel was appropriate. PSM's responsibilities also included liaising with the project designers and TJH to facilitate the design and tailor it to the conditions prevailing in the tunnel.

What was the design intent/construction sequence developed for the intersection area?

33 Mr Lloyd, a senior tunnel engineer employed by PB, provided design liaison between TJH and the project designers (PB), as well as providing tunnel engineering support to the geotechnical team. Mr Lloyd explained that excavation in the MC5B commenced in early 2003 and re-commenced in mid-August 2005. Earlier in time, Mr Gilchrist had projected the presence of the dyke in MC5B. Mr Lloyd formed the view, given the number and length of bolts and their longitudinal spacing as part of the design prepared for the area, that a safety risk might arise because of the potential for small blocks to detach and load early strength shotcrete where the dyke was encountered. After discussing these matters with the design team, the design was modified and changed to 8 bolts, 4 metres long at 1.25 metre spacings. This modification, or variation, as Mr Lloyd described it, was reflected in drawing TW03-0043-5-0 which was issued on about 25 August 2005. Shortly after, Mr Lloyd visited the area with Mr Gilchrist and observed the exposed dyke on the right-hand side of the drive. As an added precaution, he recommended that the support density be increased by tightening the longitudinal span from 1.25 metres to 1 metre. The recommendation was maintained throughout MC5B drive.

34 On 13 or 14 September 2005, while undertaking an inspection in MC5B, Mr Lloyd saw that the operators had encountered a second dyke while drilling into the left-hand side wall. About a week later, he discussed the occurrence of the dykes with Mr Gilchrist. Mr Gilchrist had the area surveyed and on 25 September he gave Mr Lloyd a hand-drawn projection of the dykes which inferred that they would intersect at the junction of MC5B and MCAA. Mr Lloyd took a copy of that drawing to Mr Leis, a civil engineer employed by PB as part of the design team.

35 Mr Leis said he was approached by Mr Lloyd in September 2005 with an enquiry to increase the support at the intersection of MC5B and MCAA. At that time, the existing support was detailed in a document TW03-0059-0-0. Mr Lloyd showed Mr Leis the hand-drawn diagram which inferred that dykes would intersect at the MC5B and MCAA intersection. Together with Mr Lloyd, Mr Leis measured and determined that the span would be 15.5 metres across the diagonal of the tunnel intersection. After seeking advice on a suitable bolt length for the span (from Loganathan Nagendran, employed by PB as a senior geotechnical/tunnel engineer), he determined that for spans up to 16 metres, 5 metre bolts may be adopted, and on the extremities, 5 metre bolts, for spans of up to 20 metres in good quality shale and sandstone may be supported.

36 According to Mr Leis (and confirmed in various drawings) the width of the MC5B drive was 9.46 metres. An initial bolting arrangement to accommodate this was 9 rock bolts at 4 metres long at 1 metre longitudinal spacing with spider plates introduced into the intersection design to ensure the safety of the underground workers. Five metre bolts were specified as the primary support to ensure that the 15 metre span at the intersection across the diagonal was supported with three 4 metre rock bolts and spider plates specified to stitch the dyke-affected eastern side wall and spot bolts as required by the geotechnical engineer. In addition, a floor to floor 200 mm shotcrete arch was required to be installed in a two-pass sequence. In an interview, Mr Leis explained the revised design (as at September 2005) for ground support at the intersection of MC5B and MCAA as follows:

The design for the intersection required a full face construction sequence of a 1500mm face advance and at no time should the unsupported face advance beyond 2.5 metres. This allowed the bolts to installed within 1m of the face. Once the excavation is completed to a full face the next step was to install one row of 4m rock bolts and spider plates and a pre-tension of 50 Kilo Newtons and fully grout. Next step was to apply 100mm of initial lining of fibre reinforced shotcrete to the crown and walls from floor to floor as depicted on the drawing. The next step was to install 5m rock bolts throughout the intersection and pre-tension to 50 Kilo Newtons and fully grout. The last step was to apply 100mm of final lining FRS to the crown and the walls, floor to floor as shown on the drawing TW03-0059-1-0 which is the certified for construction drawing for the intersection.

37 The revised design was reflected in the drawing by Mr Leis, TW03-0059-1-0 dated 29 September 2005. Mr Gilchrist, in an interview, confirmed that the revised design reflected in the drawing was the bolting pattern intended to be used at the intersection. Mr Leis, in his interview, stated that the competency of the excavation to prevent roof collapse relied upon the crew installing the required support in a timely manner, and, that it was essential to ensure that the ground support was installed in accordance with the construction sequence (the specified bolting patterns and floor to floor 200mm of shotcrete), otherwise the integrity of the support system would be compromised.

Non-compliance with design intent and construction sequence by TJH

38 The evidence establishes that TJH failed to follow the revised design for the construction sequence at the intersection of MC5B and MCAA. In summary, the shotcrete, which provided structural support to the roof, was not applied floor to floor. Nor was it applied to the specified thickness (initial application 100 mm to crown and walls with final application 100mm to crown and walls). This meant that not only was there an absence of roof support but, because the shotcrete was not self-supporting, it added an extra load to the roof. In addition, many of the rock bolts, which were meant to anchor, or secure, the shotcrete to the roof, failed. Mr Kotze explained the consequences of this in his Report in the portion extracted above, headed "iv) The inadequacy of the tunnel roof installations".

39 The shotcrete was not applied floor to floor as a result of a procedure adopted by the tunnelling crew referred to as "benching". Benching, and its influence on the ground support system at the intersection, was explained by Mr Kotze in his Report as follows:

Benching is the process whereby the full height of an underground excavation is achieved in 2 or more passes, with an interim "bench" (or benches) remaining for subsequent excavation to achieve the full height. The design height of the MC5B/MCAA intersection was approximately 8.5m and benching was employed.

As described above, the ground support system adopted in the intersection included an initial 100mm thick application of shotcrete, with a subsequent second application also 100mm thick, to achieve a final 200mm thick shotcrete lining to effectively act as a supporting arch from floor to floor. An impact of benching however, is to preclude the achievement of the full shotcrete lining, until the bench excavations have been completed. Throughout the duration of the time period between initial excavation and final bench excavation, the shotcrete component of the roof support system remains incomplete, as does the corresponding level of roof support. Furthermore, an initial layer of shotcrete lining to the floor of the initial bench, is undercut by the excavation of a subsequent lower bench. This effectively removes the basal support of the initial shotcrete, with a corresponding loss of support to the roof. The overall effect of this process is to enable the roof to be less than fully supported, for various periods of time up to the final establishment of the double shotcrete thickness from floor to floor at final level. During periods of less than full support, the potential exists for roof strata to delaminate and for roof instability to develop.

40 Another critical factor in which the design intent was compromised involved advancing the right-hand drive of the MCAA which increased the span at the intersection at the time of the roof collapse to 22 metres. The effect of this disparity on the stability of the roof at the intersection was described by Mr Kotze in his Report:

At the time of the incident, the northern or right-hand side of the MCAA down drive from the intersection, had been advanced by more than the prescribed 1.5m. (Figure 1 and Reference 4). It is understood that the MCAA down drive had been partially installed on its right-hand side only with a number of 4m long rock bolts and with a single application of shotcrete of unknown thickness. (Figure 8). The partial excavation of the down drive on its' right-hand side only, prevented the establishment of a shotcrete arch across the full drive width. See Plates 12 and 15. The excavation and ground support sequence had not been completed. The excavation roof was therefore less than fully supported. The limited support in place at the time could not accommodate the geological conditions encountered in the roof and roof collapse occurred.

41 A further factor involved the difficulties faced by the tunnelling crew with tensioning and grouting the rock bolts at the intersection. These difficulties are well-documented in statements taken from the tunnelling crew who were working in the intersection during the period of the charges. Mr Baker said the bolts "hadn't taken up" and that they had trouble grouting them. Mr Shaw said some bolts would not tension and he had concerns because the ground being rock-bolted was so soft. Mr Swan recalled, "a lot of trouble tensioning" whenever the crew was close to the dyke. He estimated that about 90 per cent of bolts would not tension properly. Mr Watson said he was aware of tensioning problems with the rock bolts. He estimated that about three to four out of ten rock bolts did not tension properly.

42 Mr Kotze, in his Report, considered that the rock bolts installed at the intersection were not properly installed with the result that they would have had a minimal effect in providing roof support. He considered the malfunction of the rock bolts a "very serious issue" and a primary factor in causing the roof collapse on 2 November 2005. He added, by way of further clarification, the following observations:

... the support of the intersection and its transition zones was to be achieved by the composite effects of a 200mm thick shotcrete lining from floor to floor, and arrays of CT rock bolts. Prior to the completion of shotcreting/benching/shotcreting as necessary to achieve the full shotcrete lining (arch) from floor to floor, the support of the roof was reliant on the efficacy of the CT rock bolts. The failure of bolts to tension/end anchor and/or to achieve full grouted bond strength, would effectively leave those locations with very little if any roof support. This is considered to be a very serious issue in terms of both safety to personnel beneath such roof areas, and the potential for delamination and larger scale instability mechanisms to develop in the roof.

43 PSM appeared to be aware that the design intent for the intersection was not followed.

44 Following inspection of the area, Mr Gilchrist recorded his observations and recommendations in documentation headed "Ground Classification & Ground Support Determination" (GC & GSD document) and mapping sheets. In a GC & GSD document dated 21 October 2005, Mr Gilchrist referred to a bench which he recommended should be excavated and the side walls trimmed "to finish floor level". As a next step he recommended "shotcrete to floor, 200mm thickness (min)". In an interview, Mr Gilchrist said that the "as excavated" ground and the ground support at the intersection did not meet the design intent because the shotcrete application to the walls was not satisfactory in that it was not thick enough and did not extend to the excavated floor level. He also referred to partial application on the back wall of MC5B by reference to a photograph which showed exposed shale on the wall. He confirmed that on 27 October 2005, he recommended in a GC & GSD document that three rows of bolts be installed on the MC5B back wall to add compression to the potential wedges present there. The following day, he recorded on a GC & GSD document that the bolts had not been installed. He said he had been concerned about this although he said that it was not an immediate safety issue in terms of overhang, adding that it was prudent to have the rock bolts installed to ensure the long-term integrity of the tunnel side walls.

45 On 31 October 2005, he recorded in a GC & GSD document a note which stated:

* 200mm shotcrete req'd to the floor as soon as possible. I understand 1m benching - Thursday!

46 The document also recorded that the bolts had still not been installed on the MC5B back wall. Mr Gilchrist said they were installed some time between 7am on 31 October 2005 and 7am on 1 November 2005. On 1 November 2005, Mr Gilchrist recorded in a GC & GSD document that ground conditions at the intersection were poor, shotcrete was cracking and did not extend to the floor and that 4-metre bolts in the MCAA crown and shoulder needed replacing. He said in an interview that he did not know whether these matters were rectified prior to the roof collapse.

47 Mr Gilchrist was also aware that the tunnelling crew on 1 November 2005 had excavated the right side of the MCAA down drive by approximately 8 metres in advance of the left-hand side.

Particular c of s 8(1) charge/Particular d of s 8(2) charge: whether failure to implement and maintain adequate system of communication or liaison between PSM and TJH

48 Sub-particulars (i) and (ii) of Particular c (s 8(1) charge) and Particular d (s 8(2) charge) substantially deal with the same alleged failures and may be dealt with together. Those alleged failures concern a failure to provide adequate notice to TJH of its non-compliance with the design and the need to obtain a new design and construction sequence for the intersection and down drive of the MCAA.

49 In oral submissions, the prosecution sought to emphasise that it was not enough to simply inform TJH of its non-compliance and the necessity to obtain a new design. The evidence on this aspect demonstrates that TJH knew it was not complying with the design or with the construction sequence. According to the prosecution, the sub-particulars deal with the failure to notify TJH of the significance of its non-compliance. I agree that this should be the approach adopted for consideration of the particulars. PSM were seconded to the LCT project with the requisite expertise and experience of geological conditions in the Sydney basin. They were engaged to assist both in the design stage and the construction stage of the project. It was part of PSM's responsibilities and the expectation of both TJH and PB that PSM personnel would discharge those responsibilities. PSM was expected to alert TJH and PB to the significance of the geotechnical data obtained and the prevailing ground conditions in the area of the intersection and compare those matters with the design as formulated, so that the tunnel support could be revised.

50 The evidence demonstrates that PSM failed to notify TJH of the significance of its non-compliance with the design intent and to adequately notify TJH of the effect of what was happening and to adequately notify TJH that it should obtain a new design and construction sequence in the area of the intersection.

51 Mr Jones, a tunnel engineer employed by TJH, had access to and read the GC & GSD documents prepared by Mr Gilchrist on a daily basis. He passed on the information in those documents to the project manager, Duncan Shires. He was aware of the design intent and the construction sequence to be implemented at the intersection. He believed that the support regime was appropriate for the ground conditions encountered at the intersection prior to the roof collapse. He added that, "I'm not a designer, the designers told us that so I presume it's appropriate". He also believed that at the time and location of the roof collapse the "as excavated" ground and ground support installed met the design intent, when clearly it did not. He was aware that the shotcrete had to be applied floor to floor with a thickness of 200mm. At the same time he described the construction sequence as involving benching which undercut the shotcrete so that it was not applied floor to floor. Referring to the application of the shotcrete in the area of the intersection, he said, "Not extending to the floor, I imagine you help, but that was part of the sequence, that was part of the agreed design". During an interview it was suggested to him that the design intent and the construction sequence in the area of the intersection was not being followed because the shotcrete lining applied was not thick enough. Mr Jones' response was, "well, I think the shotcrete was thick enough". He also believed that the rock bolts installed, tensioned and grouted at the intersection were performing their intended purpose. He was not aware of anyone having a concern with the effectiveness of the rock bolt support regime.

52 Mr Gilchrist's observations in the GC & GSD document dated 1 November 2005 were shown to Mr Jones during his interview. That document recorded that the ground conditions were poor, shotcrete was cracking and did not extend to the floor, and 4-metre bolts in the MCAA crown needed replacing. He disagreed with the observations adding:

... I can't tell you anything about it. I didn't see the cracks myself and they were not brought to my attention when I was down there at 7am and Daryl and Phil Lloyd were also there. To deal with this cracking in the chamfer area this is detailed in the recommendation and was completed that day. No recommendation is given to deal with any other cracking. With respect to the bolts I can say with certainty that the brow bolts shown in the hand drawn sketch were installed. These brow bolts are the replaced/installed bolts in the crown and shoulder and they were done. My recollection is that the shotcrete extended to the floor.

53 In his interview, the following exchanges occurred:

Phil Lloyd has also stated that he made support recommendations to Daryl Gilchrist verbally on 1/11/05 to install additionally to the design requirements "9-10 spiling rock bolts across the crown of the tunnel and to install rock bolts underneath the brow to support the unsupported brow and to increase the thickness of shotcrete to 200 mm floor to floor immediately, and not to excavate any further until the recommendations were carried out". Were you aware of these recommendations?

A. No.

Were you aware of Phil Lloyd's recommendation to carry out his recommendation immediately and not to excavate any further until the recommendations were carried out?

A. No.

Would you expect to be made aware of Phil Lloyd's recommendations given his concern that his recommendations be carried out immediately and not to excavate further?

A. Absolutely. I would expect to be informed through the GSD.

(The "GSD" referred to by Mr Jones I take to be a reference to the GC & GSD documents prepared daily by Mr Gilchrist.)

54 This evidence reveals that Mr Gilchrist's daily observations and recommendations made in the area of the intersection were not the subject of further communication. Nor was the significance of his observations the subject of further communication to TJH. The significance of benching, for example, as explained by Mr Kotze, was that, it had the capacity to compromise the roof support because it compromised the capacity of the shotcrete to be self-supporting.

55 Mr Clark was responsible on behalf of PSM for monitoring the data collected by PSM employees and the mapping. He was also responsible for writing weekly monitoring reports and liaising with Mr Lloyd and others, including construction engineers and supervisors, as regards design requirements. Mr Clark did not liaise with construction engineers or supervisors with regard to design requirements. Instead, he believed that Mr Lloyd dealt with those issues. In an interview, he gave the following responses in relation to this issue:

Wasn't it your role as the Senior Rock Mechanics Engineer to liaise with construction engineers and supervisors regarding the design requirements?

A 97. I believe so. However as Phil Lloyd was the designer's representative he would generally deal with those issues specific to that intersection because the design had changed when it was discovered the dyke would go through the intersection. Also because Phil Lloyd was often with Daryl in the week before the failure, then he was directly liaising with TJH. Also because his company had the responsibility of the design.

Who are the two parties to the consultancy agreement that sets out the Senior Rock Mechanics roles and responsibilities?

A 98. PSM & TJH

Why does it appear that you have relied on Phil Lloyd of PB to carry out some of the roles and responsibility in relation to the intersection?

A 99. I did not rely on Phil Lloyd regarding my role at the intersection. But as stated previously in question 97 I understand Phil Lloyd was taking the designers responsibility at that intersection.

What liaison did you have with construction engineers and supervisors regarding the design requirements and benching being undertaken by TJH at the intersection?

A 100. I would talk to the site engineers and I would issue weekly reports.

56 In his interview, Mr Clark explained that he was the only senior rock mechanics engineer working on the project. With regard to sub-particulars (i), (ii) and (iv) (both charges), Mr Clark said in an interview that he liaised with TJH (construction engineers and supervisors) about the design requirements of the intersection by informing them where monitoring installations needed to be installed. Mr Clark was later asked what he did if the GC & GSD documents produced by Mr Gilchrist for the intersection recorded incidences where the design intent and the construction sequence were not being followed. He replied:

The geologist would generally raised those issue with Phil Lloyd before me, and therefore Phil Lloyd would deal with those issues, and any implications it may have on the design.

57 One of PSM's contractual obligations under the PSM Rock Mechanics Engineer Consultancy Agreement was to liaise with TJH regarding the design requirements. The obligation was to be met through Mr Clark as the Rock Mechanics Engineer. It is clear on the evidence outlined above that Mr Clark did not discharge this obligation. Specifically he did not notify TJH of its non-compliance with the design intent in the area of the intersection, effectively abrogating that responsibility to Mr Lloyd, who was employed by PB. It follows from the evidence that PSM also failed to notify TJH of the risk of rock collapse arising from its non-compliance with the design intent in the area of the intersection. Mr Kotze's observations and opinions earlier extracted from the Report demonstrate that this risk arose as a result of TJH's non-compliance. Other evidence demonstrates that the non-compliance arose as a direct result of PSM's failure to notify TJH. It also follows that because PSM failed to notify TJH of its non-compliance, PSM also failed to notify TJH that it should obtain a new design and formulate a new construction sequence for the intersection in order to avert the risk of rock collapse in the area.

58 The requisite causal nexus between the failures alleged in sub-particulars (i) and (ii) of the charges and the risk of tunnel collapse (and being struck by falling rock) has accordingly been established by the prosecution beyond reasonable doubt.

59 Under the PSM Rock Mechanics Engineer Consultancy Agreement, PSM, through its Rock Mechanics Engineer, was also obliged to analyse the tunnel mapping done by a geologist and compare the mapping to the conditions described in design reports to ensure that support regimes were appropriate and efficient. In his interview, Mr Clark was asked how he made comparisons with the design of the intersection from 27 October 2005 to 2 November 2005. He said that he compared the encountered conditions with the anticipated conditions by reviewing the mapping (done by Mr Gilchrist) on a weekly basis. Mr Clark also said the last time he visited the intersection before the rock collapse of 2 November 2005 was on 18 October 2005.

60 The mapping was done by Mr Gilchrist on a daily basis and produced by him on mapping sheets at the same time as the GC & GSD documents. It appears that both documents were submitted together for the purposes of review by Mr Clark. In a Work Method Statement prepared by TJH, Table 2 sets out the geotechnical mapping and ground support determination procedures to be followed. Part of the procedure required the shift geologist (for example, Mr Gilchrist) to submit his field maps and ground support determination advice to the senior rock mechanics engineer, that is, Mr Clark, for daily review. In his interview, Mr Clark's attention was directed to Table 2. When asked, he conceded that he did not carry out a daily review of the GC & GSD produced by Mr Gilchrist for the works in MC5B and MCAA during the period 27 October 2005 to 2 November 2005. His explanation for not doing so was that he understood that Mr Lloyd was carrying out that function. The basis of this understanding was he believed that Mr Gilchrist would generally write them in Mr Lloyd's presence.

61 Had Mr Clark conducted a daily review (and analysis), as he was obliged to do, the content of Mr Gilchrist's GC & GSD documents would have come to his attention and he would have been aware (and fully cognisant of the significance) that ground conditions at the intersection had deteriorated and were substantially worse than the anticipated ground conditions. He would also have been aware that the design intent and the construction sequence was not being followed, that is, benching was occurring, shotcrete was cracking and was not being applied floor to floor, and rock bolts were not being installed in the MCAA back drive in a timely manner. Mr Kotze's description of the ground conditions prevailing at the intersection, and the conclusions he derived from TJH's non-compliance with both the design intent and the construction sequence (namely, a resultant risk of tunnel collapse) are matters that I have already dealt with and referred to in some detail. They need no repetition. PSM's expertise, no doubt, would have enabled it, had it adequately analysed the data and compared it to the design, to arrive at a similar conclusion. Its failure to do this establishes beyond reasonable doubt the requisite causal nexus between the risk and the failure alleged in sub-particular (iii) of both charges.

62 Sub-particular (iv) has been considered to some extent in this judgment. I have already found that Mr Clark did not adequately liaise with TJH regarding the design requirements of the intersection, instead effectively abrogating that responsibility to Mr Lloyd whom he assumed had discharged it. According to Mr Clark, he discharged his responsibilities regarding design requirements by informing the construction engineers and supervisors where monitoring installations needed to be installed.

63 PSM also had a contractual obligation to keep adequate records of monitoring activities for the use and consultation by TJH (and PB, the designers) and to manage and co-ordinate the installation of the monitoring equipment on a monthly basis and record relevant entries in a document. One such document headed "Project: ISO23" records that at a particular point (point no. 23.2) on 24 October 2005 significant subsidence of 9mm occurred in the MCAA up drive at chainage 494 metres, only some several metres distance from the intersection, and only several days before the roof collapse in the intersection. Mr Clark's evidence (that he only informed TJH where monitoring installations needed to be installed) indicates that TJH was not advised of the subsidence which occurred on 24 October 2005. Mr Kotze, in his Report, said that an ongoing review of monitoring data as it came to hand and the expansion of the monitoring programme at locations warranting closer attention, such as the intersection, would have been an integral component of a joint review process between PSM, TJH and PB. According to Mr Kotze, as part of that joint review process, and in consideration of the difficult geological conditions being encountered and the settings/implications of the intersection, it would have been possible to increase the frequency of monitoring measurements at 23.2 when excavations entered the intersection. Mr Kotze concluded that had this been done, the risk of roof collapse would have been reduced. The matters underpinning this conclusion were set out by Mr Kotze in his Report:

In generating and interpreting such monitoring data and in association with the other review procedures that could have been undertaken jointly by the tunnel geologist and the design engineers as described above, the geological conditions encountered, the performance of the roof support installations, and the performance of the rock masses in and above the roof of the intersection, could have been assimilated. This would have enabled a comprehensive assessment to be jointly made of all aspects of the tunnelling and support processes. The potential would thereby have been created for deficiencies in the excavation and support activities to have been recognised and rectified. Design and construction alternatives could have been engineered and implemented as appropriate, thereby reducing the potential danger or risk of roof collapse.

64 On the basis of this evidence, the requisite causal nexus is also established beyond reasonable doubt with regard to sub-particular (iv) (both charges).

65 There is considerable overlap between sub-particular (v) and sub-particular (iii) of both charges. According to Mr Clark, he monitored the mapping by the geologist by looking at it "generally ... once a week and by periodically accompanying a geologist on visits to the tunnel faces. In his weekly report, he included a summary of geological conditions and the results of the monitoring data. He did not include in the reports any issues relating to ground support because, he said, "these would generally be design issues and would be done by Phil Lloyd".

66 Mr Kotze viewed this review process of the geological inspection records as deficient and inappropriate. In this regard, he said:

... The geological inspection records provided daily accounts of difficult geological conditions, excavation sequencing and benching, and the often incomplete status of progressive roof support. Moreover, as the MC5B/MCAA intersection was progressively negotiated with its even more adverse dyke and fractured shale conditions relative to an increasing span, it is apparent that the daily geological inspection records did not trigger any design review of the adequacy or otherwise of the prevailing roof support regime with its undercut shotcrete and incomplete rock bolting recommendations. In combination with the apparent lack of a review process whereby inefficiencies in rock bolt end anchorage and grout encapsulation could be identified and rectified, it is concluded that the response and review processes to as found conditions in MC5B and the intersection prior to the incident, were deficient and hence inappropriate.

67 The evidence outlined above with regard to sub-particular (v) and the evidence I have considered in relation to sub-particular (iii) facilitates the conclusion that PSM did not adequately review the mapping or the ground classification or support types recommended by the geologists, in particular, Mr Gilchrist, during the period of the charges in the area of the intersection. My conclusion that the causal nexus between sub-particular (iii) and the risk of tunnel collapse has been established applies with equal force to sub-particular (v). Proper review of the geological conditions would have alerted PSM to the deteriorating conditions in the intersection and to the fact that TJH had deviated from the design intent, resulting, in turn, to a risk to the safety of the workers in the area by reason of the risk of tunnel collapse. Sub-particular (v) of both charges is therefore established beyond reasonable doubt.

Particular d of s 8(1) charge/Particular e of s 8(2) charge: whether failure to implement and maintain adequate system of communications or liaison between PSM and PB

68 Sub-Particulars (i) of Particular d of the s 8(1) charge and Particular e of the s 8(2) charge allege a failure by PSM to notify PB. The sub-particulars are otherwise identical to sub-particular (i) of Particular c of the s 8(1) charge and sub-particular (i) of Particular d of the s 8(2) charge. The evidence considered with regard to those latter sub-particulars is equally applicable to the sub-particulars presently under consideration and accordingly that evidence will be taken into account, and the findings made will be substantially based on that evidence.

69 Mr Lloyd regularly accompanied Mr Gilchrist on his daily visits to the area of the intersection. He had regular discussions with Mr Gilchrist regarding the ground conditions in the area and had input into what ground support should be installed. Mr Lloyd's principal role was to provide a design liaison between the constructors and the designers. One of the principal designers on the project, in the area of the intersection, was Mr Leis. His role in revising the design requirements for the intersection and surrounding area as the excavation progressed, especially after September 2005, has been set out in detail. Mr Lloyd was in a position to pass on the information contained in Mr Gilchrist's GC & GSD documents and his mapping sheets to Mr Leis, as well as to the other designers, namely, Mr Maconochie and Mr Nagendran. Whether he did or not, or whether he appreciated the significance of the information contained in those documents is not an issue which it is necessary for the Court to consider, in any detail. Of greater relevance to the issue presently under consideration is whether PSM passed on the information. The evidence demonstrates that it did not.

70 Mr Leis, in a response to a question about whether the ground conditions at the intersection raised concerns with the design team at PB, said he was not made aware of the actual ground conditions encountered at the intersection. During his interview, he said that the competency of the excavation in order to prevent tunnel collapse relied upon the TJH crew to install the required support in a timely manner, and, that it was essential to ensure that the ground support was installed in accordance with the construction sequence, otherwise the integrity of the support system would be compromised. He referred (by reference to a diagram shown to him during the interview) to the excavation taking place on 1 November 2005 and confirmed that it disclosed that the excavation in the right-hand side of the drive (of MCAA lower) was more advanced than the left-hand side up to a distance of 6-8 metres. He said that without completing the staged sequence at that point (by excavating the left-hand side of the tunnel and installing a full support system), the excavation was non-compliant beyond that point. Prior to the tunnel collapse, Mr Leis was not made aware that TJH was not complying with the design. Nor was he aware whether the information (concerning non-compliance by TJH) was provided to other PB designers. He said that if he had become aware that the construction sequence at the intersection was not complying with the design, he and the PB designers would have taken the following steps:

PB would seek details as to the extent of any non-conformance and provide details of the actions required to ensure the excavation could be pulled back into sequence. The remedial measures would be provided so that support could be installed in a safe manner.

71 Mr Leis commented on the risks attendant upon not excavating MCAA lower in accordance with the design:

PB developed a series of specifications, design drawings and reports in accordance with the SWTC and the MCOA. This documentation followed a series of analysis undertaken on a project wide basis and for specific design elements. This documentation underwent a process of design and review. Following the agreement by all stake holders the design was certified for construction. In the event that MCAA lower was not being constructed in accordance with the design the risk of instability or collapse increases. The competency of the excavation to prevent instability is dependent upon the support being installed in accordance with the design. The design states the minimum requirements of installing a support system in a safe and timely manner.

72 The responsibility to notify PB of the constructor's non-compliance and of the consequential risk of rock collapse rested squarely with PSM. Its failure to do so resulted in the risk to the safety of the workers and residents of the unit block arising from the risk of tunnel collapse.

73 Given that PSM failed to notify PB of the non-compliance with the design intent by TJH, it follows that PSM did not adequately notify PB that it should provide to TJH a new design and construction sequence for the construction taking place in the area of the intersection (in circumstances where the design and construction sequence provided was not followed). This failure, for reasons earlier stated, and in reliance on the evidence of Mr Kotze in particular, resulted in the risk of tunnel collapse thereby causing a risk to the safety of both the workers in the area (both charges) and the residents of the unit block (s 8(2) charge).

74 Accordingly, sub-particulars (i) and (ii) of Particular d (s 8(1) charge) and Particular e (s 8(2) charge) have been established beyond reasonable doubt.

75 The design requirements for the area of the intersection, which were designed by Mr Leis, did not include benching. In his interview, Mr Leis said that if benching was required, TJH would have advised the designers. He was not made aware that benching was required in the area of the intersection. If PB had been made aware he said that after due consideration of all available information, design factors and an assessment of the conditions, PB would have provided a sequence for installing the support safety. Mr Leis also commented on the effect of benching on ground stability at the intersection. In that regard, he said:

If benching results in the incomplete installation of the ground support system then the ground may be overstressed and the potential for fallout or overbreak is increased.

76 Mr Clark did not raise the fact (with TJH or with PB) that benching was not included in the design documentation for the intersection. He could not recall if benching formed part of the design intent at the intersection. Later he said that he assumed that benching formed part of the design documents for the intersection because that was part of the construction sequence adopted by TJH.

77 It may be inferred from this evidence that PSM did not adequately notify the PB designers that the construction sequence being employed in the intersection and the MCAA down drive included benching. Mr Kotze's evidence to the effect that benching in the area exacerbated the risk of tunnel collapse has been earlier set out. The evidence in combination establishes sub-particular (iii) (both charges) beyond reasonable doubt.

78 Under the design intent, shotcrete in the area of the intersection was to be applied in two applications to a thickness of 200mm and was to extend floor to floor. As the evidence reveals, this did not occur. Benching in the area of the intersection prevented the shotcrete being applied floor to floor. As Mr Kotze pointed out, the effect of benching was to remove the basal support of the initial shotcrete with a corresponding loss of roof support. He said that during the period when the roof lacked full support, the potential for the roof strata to delaminate existed and roof stability could develop. When the excavation proceeded on the right-hand side of MCAA lower in advance of the left-hand side, this, according to Mr Kotze, prevented the establishment of a concrete arch across the full drive width with the result that the excavated roof was not fully supported. This, together with the limited support in place at the time (including the partial application of shotcrete), resulted in the collapse of the roof.

79 Mr Leis provided the design for the construction sequence at the intersection. It required the shotcrete to be applied to the correct thickness and to extend to the floor. He said without these measures the potential for fall out and overbreak was increased.

80 Mr Clark maintained in an interview that he was not aware that the shotcrete applied in the area of the intersection was of incomplete thickness (that is, not according to the design) and did not extend floor to floor. He said if he had been aware he would have raised the issue. The scope of Mr Clark's responsibility as the senior rock mechanics engineer for PSM suggests that Mr Clark should have, and could have, made himself aware of this aspect of non-compliance with the design. As PSM's representative with responsibility for liaising with the project designers to facilitate changes to the design, it is apparent that PSM failed to adequately inform the designers of the constructors' failure to apply the shotcrete in accordance with the design intent. Mr Kotze's observations and conclusions concerning the failure to apply the shotcrete in accordance with the design (increased roof instability lending to a risk of tunnel collapse) and PSM's failure to inform the designers with regard to the application of shotcrete in the area of the intersection led to the risk of tunnel collapse in that area. If the designers had been informed no doubt appropriate measures would have been taken to ensure that the shotcrete was appropriately applied. Sub-particular (iv) (both charges) is therefore established beyond reasonable doubt.

81 With regard to sub-particular (v) of both charges, there is ample evidence, earlier referred to, of problems encountered with the rock bolts installed in the area of the intersection. Despite this, Mr Gilchrist appeared to have no knowledge of the information in shift reports that minimal bolts were installed in the intersection after 27 October 2005.

82 The evidence indicates that because of the difficulties encountered with tensioning and grouting of the rock bolts by the tunnelling crew, the drill bit size was reduced. According to Mr Kotze, the rock bolts were installed at the intersection in under-sized drill holes with a resultant limited capacity to achieve grout encapsulation. In addition to these problems, rock bolts used to replace failed rock bolts also failed to tension.

83 In an interview, Mr Clark said he was not aware of any issues relating to the tensioning or grouting of rock bolts in the intersection. He was also unaware, he said, of under-sized drill holes for the rock bolts in the area. Insofar as he was aware, neither he nor any other person on the project had concerns about the rock bolts failing to tension in the intersection area.

84 In his interview, Mr Leis was asked the same question as Mr Clark with regard to rock bolts installed at the intersection failing to tension. He said he was not aware of that matter. Nor was he aware of whether rock bolt installation reports were supplied to PB. He was not made aware of any issues relating to the incorrect installation of rock bolts at the intersections and he said he was not provided with shift activity reports for the intersection.

85 Part of PSM's responsibilities on the LCT project, through Mr Clark as the senior rock mechanics engineer, involved liaison with the project designers (PB) to facilitate changes to the design in order to tailor it to the conditions encountered. Rock bolting formed an integral and critical part of the design for the roof support at the intersection as demonstrated by the revised TW03-0059-1-0. Mr Kotze, in his Report, observed that the support of the roof was reliant on the efficacy of the rock bolts and their failure to tension, and anchor or achieve full grouted bond strength in particular locations, would effectively leave those locations with very little, if any, roof support. Mr Kotze considered this to be a very serious issue in terms of the safety of personnel working beneath those locations. It may readily be inferred from his evidence that the deficient rock bolts installed in the area of the intersection in the days preceding the roof collapse also jeopardised the safety of the residents of the nearby block by reason of the risk of tunnel collapse.

86 These matters, when taken together, establish beyond reasonable doubt that PSM's failure to adequately liaise with the project designers to facilitate changes to the design, with regard to the performance of the rock bolts at the intersection caused a risk to the safety of both the workers in the crew and to the residents of the unit block.

Particular e of s 8(1) charge/Particular f of s 8(2) charge: PSM failed to prevent its employees/adequately advise that workers should be prevented from performing work in the down drive of the MCAA including its intersection with MC5B

87 There is little doubt, based on the evidence earlier traversed, that PSM during the period of the charge, failed to prevent its employees and failed to advise other workers in the area of the intersection that they should be prevented from performing work there. Equally there is little doubt, based on the evidence, that during that period, conditions in the area had deteriorated to such an extent that without appropriate support mechanisms, which were not in place, the roof was in imminent danger of collapse. Accordingly, the requisite nexus between the failures alleged in each Particular and the risk to the safety of personnel working in the area is established beyond reasonable doubt.

Orders

88 The Court makes the following orders:

1. In Application for Order IRC 1991 of 2007, the defendant is found guilty of the offence and convicted.

2. In Application for Order IRC 1992 of 2007, the defendant is found guilty of the offence and convicted.

3. Both matters are set down for a directions hearing at 10am on Friday, 24 February 2012 for the purpose of setting dates for sentence hearings.

Amendments

20 February 2012 - Amended "what was the design intent/construction sequence developed to the intersection area" to read as "what was the design intent/construction sequence developed for the intersection area"
Amended paragraphs: Catchwords

20 February 2012 - Amended "non-compliance with design intent and construction by Thiess John Holland (TJH) to read "non-compliance with design intent and construction sequence by Thiess John Holland (TJH)"
Amended paragraphs: Catchwords

20 February 2012 - Amended fourth sentence - "agreed" to read "agree"Amended last sentence of paragraph 49 - "... conditions at the crown ..." to read as "... conditions in the area ..."
Amended paragraphs: Paragraph 49

Decision last updated: 20 February 2012