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Investigation and Design of Tunnels and Underground Mining Operations

PSM has a substantial presence in the areas of tunnel design and construction supervision. This has been via significant infrastructure projects such as:

The Eastern Distributor road tunnel (Sydney)
PSM was responsible for the piggy back tunnel concept, the design of all temporary and permanent support, mapping and monitoring during excavation, and the supervision of support installation;

The Burnley Tunnel - road (Melbourne)
After failure of the invert and sidewalls prior to tunnel opening, PSM was given the responsibility for the design and implementation of all remedial works; a project which continued through 2000 and 2001 and costs more than $100million;

The three underground station caverns of the Epping to Chatswood Underground Railway Line (Sydney)
Up to eight PSM personnel were seconded to the Thiess Hochtief Joint Venture to be responsible for all mapping and monitoring, and the requirements for temporary support.
PSM designed the 200m of soft ground twin rail tunnels beneath the operating North Shore Railway;

The North South ByPass Tunnel – road (Brisbane)
Dr Philip Pells was Chairman of the Engineering Taskforce, which completed the pre-feasibility study of the tunnel on behalf of the Brisbane City Council;

The Lane Cove tunnel – road (Sydney)
PSM seconded the lead designer for the eastern section of the twin two lane tunnels which had as low as 3m rock cover yet beneath 18m of fill and the operating Gore Hill Freeway.

The Airport Link – road (Brisbane).
PSM provided geological and engineering skills to the design team.

The M2 tunnels – road (Sydney)
PSM is designing the support and construction sequencing to enable the existing 2 and 3 lane tunnels to be widened.

2009
Airport Link, Brisbane	PSM is part of the team designing the roadheader tunnels for Thiess-John Holland.
Vulture St Busway Tunnel, Brisbane	Assessment of existing 100 year design life concrete lining.
CBD Metro, Sydney	Tender design for Leighton-Seli bid for 7km long, twin tunnels and 6 underground stations in Sydney’s CBD.
M2 Tunnel, Sydney	Widening of an existing 2 and 3 lane wide tunnels.
2008
M4 East, Sydney	Advisor to the RTA for M4 East road tunnels.
Top Ryde Tunnel, Sydney	Review of tunnelling conditions for tenderer of road tunnel underneath Lane Cove Road.
Buranda Busway Tunnel, Brisbane	Advice in relation to cracking in concrete lining.
2007
Sunflower, NZ	Scoping study into hydroelectric scheme involving 30km of tunnels, South Island, NZ.
Underground Mine, Indooroopilly QLD	Review of stability conditions of the Queensland University’s Experimental Mine, which was excavated in the 1920’s and 1950’s.
Desalination Plant, Sydney	Design review of twin 4m diameter TBM for a contractors tender submission.
Energy Australia, Sydney	Option studies for cable tunnels in Sydney.
Airport Link, Brisbane	Part of the design team for Thiess-John Holland tender.
2006
Lane Cove Tunnel, Sydney	Provision of Principal Engineer as Design Leader for the section of tunnel beneath the backfilled Artarmon brick pit. Provision of up to eight staff responsible for geological mapping and instrumentation.
North-South Bypass Tunnel, Brisbane	Provision of Principal Engineer as Chairman of the Engineering Taskforce.
Epping to Chatswood Rail Link, Sydney	Advice in relation to subsidence impact of the rail tunnels.
2001-2005
Energy Australia Tunnel, Sydney	Design of 2 km nominally 3 m diameter fully tanked tunnel. Provision of specialist advice in regard to groundwater inflows into the tunnel, groundwater chemistry assessment, and grouting requirements. Geotechnical model and support design for an unsuccessful tender of a 3.5m span 2km cable tunnel.
Transgrid Tunnel, Sydney	Geotechnical model and support design for an unsuccessful tenderer of a 3.8m diameter 3 km long cable tunnel. Detailed mapping of tunnel in an area flagged as a latent condition claim, assessment of groundwater inflows and associated surface settlements, advice in regard to grouting to control groundwater inflows. Design of remediation support.
Lane Cove Tunnel, Sydney	Provision of Principal Engineer as Design Leader for the section of tunnel beneath the backfilled Artarmon brick pit. Provision of up to eight staff responsible for geological mapping and instrumentation.
Epping to Chatswood Rail Link, Sydney	Geotechnical model and support design for an unsuccessful tenderer for a 22km railway tunnel and 5 underground stations. Review of permanent support designs on behalf of Thiess Hochtief Joint Venture; provision of up to eight site staff responsible for geological mapping and instrumentation of the caverns. Separate contract for the installation of surface and groundwater monitoring along the roof of the TBM tunnels. Provision of up to eight staff responsible for geological mapping and instrumentation. Design and construction supervision of 170 m soft ground tunnel work at Chatswood.
North-South Bypass Tunnel, Brisbane	Provision of Principal Engineer as Chairman of the Engineering Taskforce to assess and plan for the prefeasibility study of a 5 km long twin, 2-lane tunnel, passing beneath Brisbane River.
Eastern Freeway Tunnel, Melbourne	Team member for technical evaluation of three tenders submitted for design and construction of a twin, 3-lane tunnel beneath Mullum Mullum Creek. The project was cancelled and reborn as the Mitcham-Frankston Freeway.
Lane Cove Tunnel, Sydney	Provision of Principal Engineer as Design Leader for the section of tunnel beneath the backfilled Artarmon brick pit. Provision of up to eight staff responsible for geological mapping and instrumentation.
North-South Bypass Tunnel, Brisbane	Provision of Principal Engineer as Chairman of the Engineering Taskforce.
Mitcham-Frankston Freeway, Melbourne	Preparation of engineering geology and hydrogeological models for one of the two project bid teams.
Burnley Tunnel, Melbourne	Design and implementation of remedial works for the invert of the Burnley Tunnel including design and supervision of a major programme of micro-fine cement and chemical grouting to reduce inflows into the tunnel. Provision of expert evidence in dispute relating to failures of the invert and portions of the sidewall of the Burnley Tunnel, which occurred prior to first planned opening.
Cross City, Sydney	Geotechnical model and support design for an unsuccessful tenderer of twin lane twin tube 2 km long road tunnel. Value engineer for the contractor of a twin lane twin tube 2km long road tunnel.
Parramatta-Chatswood Railway	Geotechnical model and support design for an unsuccessful tenderer for a 22km railway tunnel and 5 underground stations.
Brisbane S1 Sewer	Expert advice in regard to Latent Conditions claim.
1993-2000
Melbourne City Link	Leader of design team for remedial measures for the Burnley Tunnel, including some 6000 ground anchors and major cement and chemical grouting works, involving some 13,000 grout holes, 280m³ of cement grout and 100,000 litres of chemical grout.
Cross City, Sydney	Advisors to RTA in regard to geotechnical investigations, preparation of tender documents for investigations, adjudication of tenders and review.
Parramatta-Chatswood Railway, Sydney	Geotechnical model of a 10km section of the proposed railway tunnel. Independent review of the EIS for the Dept of Urban Affairs and Planning.
Northside Storage Tunnel	Specialist geotechnical advice in relation to ground support in particular tunnelling beneath valleys and stress-induced failures.
Picnic Point – Haymarket cable tunnel	Preliminary evaluation of tunnelling methods and costs.
M5 East Tunnel, Sydney	Subsurface investigations preliminary support design and hydrogeological investigations for the feasibility study of a twin tube freeway tunnel in Hawkesbury Sandstone. Design verification of 4km long road tunnel and associated earthworks. Reviewing and reporting tunnel monitoring data.
Bakun Hydro Electric Scheme, Philippines	Assessment and interpretation of stress measurements with respect to need for steel lining of headrace tunnel. Capacity of support during dewatering.
Eastern Distributor, Sydney	Design of primary and permanent support for the 4 km dual, three lane, double-deck tollway tunnel in Hawkesbury Sandstone. The concepts of the double-deck tunnel with support of the upper carriageway on bridge planks supported by narrow rock ledges were PSM innovations. Supervision of excavation and support works during construction.
Nth Quay to Brisbane Creek Sewer	Assessment of geotechnical conditions in Brisbane and review of tunnel support for tender.
West Ryde Stormwater Tunnel, Sydney	Review of ground conditions in paleochannel and assessment of appropriate tunnelling conditions through soft clay; advice in relation to a possible Latent Conditions claim.
Eastern Distributor, Sydney	Additional site investigations and design of primary and permanent support for one of the submissions for the proposed 4 km dual, three lane tollway tunnel in Hawkesbury Sandstone.
Homebush Olympic Rail Tunnel and Station	Field investigations for final design, development of geotechnical model, mapping during tunnelling. Design of soil nail support system for the Station.
M2 Tunnel, Sydney	Review consultant for the RTA. Twin tube road tunnel in Hawkesbury Sandstone.
Wombarra Drainage Tunnel, NSW	Specialist NATM advisor to Transfield under the contract; involving weekly inspections and formulation of support requirements.
Crafers Tunnel, Adelaide	Specialist advice to the prime consultant, Maunsell, in regard to primary and permanent support for the tunnel.
Ballarat Gold, Victoria	Investigation, design of support and field advice during construction of 800m long decline in weak, squeezing ground.
Elouera Colliery, Port Kembla	Investigation and design for a new mine entry comprising a 50m length of pipe canopy tunnel through talus and colluvium followed by about 0.6 km of 5m x 2.8m drift in the Illawarra Coal Measures.
Ulan Colliery, Mudgee	Design of support for a new decline entry for the longwall panels at the Ulan underground mine.
New Karak Tunnel, Malaysia	Review of geotechnical models and design of primary and permanent support for a two lane road tunnel in porphyry/andesite.
Southern Ring Road Tunnel, Melbourne	Review of tunnel route alignment, excavation methods and support design for two 3-lane tollway tunnels in Silurian age mudstone.
NW Sewer Tunnel, Melbourne	Expert advice in relation to a construction claim for latent conditions for a tunnel in mixed ground (basalt, clay and sands) below the water table excavated by an earth pressure balance TBM.
Crinum Mine Decline, Qld	Advice to contractor on ground support during construction of the decline.
Bannockburn Gold Mine, WA	Design of open stopes and pillar recovery options for a panel and pillar hard rock underground mining operation.
Cannington Silver Mine, Qld	Design and construction supervision of the initial 300m section of a decline through highly reactive, sheared Cretaceous age clays. This tunnel was supported by rockbolts, cable anchors and fibrecrete and it involved extensive monitoring to confirm or modify support requirements. Design of one conventional and one raise-bored shaft for the initial development of the Cannington orebody.
Boomerang Creek Tunnel	Advice to Contractor's legal team in relation to Latent Conditions claim, expert witness.
Schmitz Orebody, Western Mining	Design of artificial pillars to allow recovery of ore pillars in a post-pillar hard rock mining operation.

Innovations in Tunnelling

PSM have introduced several ideas into the design of tunnels. The ideas have been adopted by others and have become the de facto standard of road tunnel design in Sydney.

Opera House Car Park

While Philip Pells was a director at Coffey he was instrumental in the design of the Sydney Opera House Car Park. The Car Park was excavated in 1991 and remains as the world’s greatest span/depth ratio excavation supported by rock bolts and shotcrete.

In plan view the Car Park is circular in shape. This shape was selected as being the best suited for the insitu stresses and resulted in the 35m high vertical walls requiring negligible bolting.

Eastern Distributor

The innovative approach to roof support design was further developed by PSM in the excavation of the Eastern Distributor. The design process provides a quantitative estimate of the Factor of Safety for individual rock bolts, a value that cannot be determined using traditional methods of design.

The Eastern Distributor is one of three road tunnels in the world that has double deck carriageways. It is the only tunnel to have the deck of the upper carriageway supported as a bridge beam resting upon small rock ledges. For several hundred metres, the Eastern Distributor tunnel is the world’s largest road tunnel in cross section.

The rock bolts used in the Eastern Distributor provided a standard of corrosion protection that the industry accepted as being a 100-year design life.

Melbourne City Link

PSM were brought onto the Melbourne City Link tunnels in January 2000 to design and supervise remedial measures to overcome the overstressed concrete invert and to control the groundwater inflows into the tunnel. As this job was a case of forensic design rather than the design of a new project, many of the anchoring and grouting methods are unique and had to be extensively trialled with the assistance of worldwide specialist expertise. For example, the design and installation of retrofitted reinforcement for the concrete invert and sidewalls.

PSM are expert in grouting of rock masses and overstressed concrete structures. The methods developed have used the full gamut of grouts from OPC, purpose ground ultrafine cements, resins and specialist chemicals.

Anchoring of the concrete inverts has used bars of very high capacities (1000 kN working load) required to meet a 100-year design life. The holes that the bolts have been installed in had the added requirement of not acting as conduits for groundwater inflow under a working pressure of 600kPa.

The two and three-dimensional numerical modelling PSM has undertaken is at world’s best practice. PSM have used our in-house resources as well as that of the programs’ developers to extend the basic functions of these programs.

During the remediation work monitoring comprised 24 hour real-time remote robotic reading of survey targets and vibrating wire piezometers, which were downloaded to a computer logger via a modem.

Project Sites

Current Projects

Brisbane Airport Link

Brisbane’s $4.8 billion Airport Link, Northern Busway (Windsor... READ MORE

Kapit Pit Geotechnical Investigation

PSM is involved with Lihir Gold’s Kapit Pit, providing geotechnical... READ MORE