Projects

The project has won two awards from the Client RVNL and has now won the 2022 Team Award for AECOM (India)

David has been appointed as Chief Resident Engineer for the "Mahaweli Water Security Investment Program" (MWSIP). This is an extension of the Mahaweli Development Program (MDP) formulated in the 1960s to create a series of small tank cascade systems in North Central and North Provinces of Sri Lanka taking water from the Mahaweli River Basin using large transfer canals and reservoirs. The updated program is the construction of North Central Province Canal Project (NCPCP) which will be implemented in two sequential phases. Phase 1 comprises three main individual projects, namely Upper Elahera Canal Project, North Western Province Canal Project and Minipe Left Bank Canal Rehabilitation Project.

The Havieron decline passes through Permian sandstone

David was asked by Newcrest Mining to provide advice on reducing and controlling the water ingress into the excavation

Located in Uttarakhan in Northern India, the Rishikesh to Karanprayag Railway is 125km long with a significant part in tunnels and bridges spanning deep gorges and valleys of the Ganga Alaknanda Rivers.

David was appointed as Team Leader for the Project Management Consultant (PMC) of package 7 with AECOM (India). Package 7 has been divided into two packages with two separate contractors.

Package 7a has been awarded to Max HES Jv and consists of  a 7.08km tunnel and a bridge. Package 7b has been awarded to Megha Engineering and Infrastructure Ltd and consists of a 9.4km tunnel and Tilani Station.

Both tunnels consist of the main railway tunnel and an escape tunnel and are also accessed midway by adits to increase excavation progress.

Tunnelling is essentially drill and blast using NATM with soft ground sections at portals and where crossing the many faults along the alignment. The geology is essentially the Garhwal Group of the Lesser Himalayas consisting of quartzites, dolomites and phylites with some ultrabasic meta-sediments.

Phase 1A of the Lesotho Highlands Water Project includes the Katse and Muela Dams, a 45km Transfer Tunnel from Katse Intake Tower to the Muela Hydropower Station, which generates hydroelectric power for Lesotho, and a 37km Delivery Tunnel from Muela to Ash River outfall in Clarens, South Africa. This phase of the project (Phase 1A) was commissioned in 1988. Phase 1B consists of the Mohale Dam, a 32km Transfer Tunnel interconnecting the Mohale and the Katse reservoirs, the Matsoku Diversion Weir and 5.7km Tunnel from the Matsoku Diversion Weir to the Katse Reservoir; Phase 1B was commissioned in 2002.

David Lees has been appointed as Grouting Expert for the Panel of Experts for Lesotho Highlands Water Project Phase 2.

The New M5 is twin underground motorway tunnels in Sydney, 9km long from Kingsgrove to St Peters with connections to Sydney Gateway and M4-M5 Link and is part of West Connex.

David was appointed to supervise a crew from Mainmark Civil at Arncliffe to carry out post grouting of the tunnels. The role required defining the scope of works, designing the extent of the grouting and completing the task to achieve an acceptanle water ingress of 6 l/min/100m.

The tunnels at Arncliffe are 17m wide and 8m high, and 30m below surface, and pass under the Cooks River.

The Uma Oya Multipurpose Development Project (UOMDP) in Sri Lanka consists of two RCC dams and three tunnels. David Lees was appointed as Chief Site Supervisor for the construction of the 3.7km Link Tunnel and 15km Headrace Tunnel. The Headrace Tunnel was the first use of a TBM in Sri Lanka and passes through complex geology and hydrogeology requiring pre-excavation and post grouting works.

David assisted Mainmark Civil and Mining in determining a typical design for plugging the portals of Russell Vale Colliery.

The colliery is one of the oldest in Australia and the workings extend beneath the catchment of the Cataract Dam. The requirement was to determine the most feasible way to plug these portals in case of rupturing the reservoir above.

The Melamchi Water Supply Project is a 26km tunnel traversing the lower Himalayas bringing water to Kathmandu. David provided technical and contractual project management services for the client.

The company has provided an “Asset Protection Report” for an old brick lined sewer for the proposed deep basement.

David Lees was asked by URS to assist in the design of refurbishment measures and the tunnel inspection and site supervision of repair work for the Snowy-Geehi tunnel.