Some examples of recent investigations undertaken for infrastructure developments are as follows:

Tugun Bypass Tunnel, NSW/Qld

Hydrogeological analysis and numerical modelling using the FEFLOW software program was undertaken to identify dewatering and recharge requirements and groundwater drawdown in sufficient detail to allow detailed design of the tunnel structures. The dewatering and re-injection system was designed to minimize the impact on the natural groundwater regime and to meet strict guidelines set by the EPA.

Wiggins Island Coal Terminal - EIS, Qld

The groundwater regime of the area of the WICT and rail infrastructure was described based on historical data and data obtained from site specific investigations. An assessment was then undertaken of the potential impact of the development; dump station, reclaim tunnels, storage ponds placement of dredge spoil, deep cuts for rail line construction, borrow areas etc as a component of the EIS.

North-South By-Pass Tunnel, Brisbane, Qld

Evaluation of the hydrogeological regime of the inner Brisbane City area was undertaken in order to develop a conceptual hydrogeological model of the area from Bowen Hills to Woolloongabba. This conceptual model formed the basis for developing a numerical model to assess the impacts of tunnel construction beneath the Brisbane River on the groundwater regime for both environmental (EIS) and engineering issues. Assessment of the potential clogging of no-fines concrete drainage layers was undertaken.

Eastlink Tunnel, Melbourne, Victoria

A review of geotechnical and groundwater related data was undertaken in order to formulate an appropriate conceptual hydrogeological model of the area surrounding the Eastlink Tunnel and enable development of analytical and numerical groundwater models to assess the impacts on the environmentally sensitive groundwater regime during and post tunnel construction. Numerical modelling included novel methods of addressing the issue of longitudinal transference of hydrostatic pressure which may result in saline groundwater discharges and increased hydrostatic loading on the tunnel liner.

Airport Link, Brisbane, Qld

A detailed hydrogeological impact assessment was undertaken of the proposed Airport Link Tunnel. The work entailed establishment of a baseline groundwater monitoring network, collection of groundwater level and water quality data, formulation of a conceptual hydrogeological model, analytical assessment of potential groundwater inflows and numerical groundwater flow modelling using FEFLOW. The work was undertaken to assess the hydrogeological impacts in terms of engineering issues and for inclusion in the project Environmental Impact Statement.

Sydney Cross City Tunnel, Sydney, NSW

A review of the groundwater conditions including the impact of existing infrastructure (deep basement and existing tunnels) of the Sydney CBD and Woolloomooloo areas was undertaken in order to develop a conceptual model of the groundwater regime of the area which was used as a basis for the development of two numerical groundwater models covering the Cross City Tunnel alignment. Each of the models were used to assess the long-term groundwater inflow rates to the tunnel and the level and rate of water level drawdown in the overlying rock mass and in particular the overlying unconsolidated, saturated sediments. The data was used by the client to assess potential settlement and associated impact on existing infrastructure. 

Chevron Renaissance Tower, Gold Coast, Qld

Numerical simulation of dewatering of a 30m thick sandy aquifer to enable basement excavation for the proposed Chevron Renaissance Tower No 3 located at the center of the Gold Coast CBD. The objective was to design an optimum dewatering and re-injection system that would allow excavation in dry conditions and at the same time limit the drawdown outside the excavation to levels preventing settlement beneath surrounding buildings.

Northern Busway Brisbane, Brisbane, Qld

A hydrogeological impact assessment was undertaken as part of the Concept Design and Impact Management Plan (CDIMP) for the Northern Busway Project. The work was undertaken included numerical modelling of the potential cumulative  impact on the hydrogeological regime of the Airport Link Project which follows a similar alignment.  

Toowoomba Bypass Tunnel, Qld

Assessment of groundwater impacts of a proposed pilot tunnel for the Toowoomba Warrego Highway Bypass Tunnel. Included conceptualization of the hydrogeological regime, analytical prediction of potential pilot tunnel inflows, numerical modelling of the impacts of pilot tunnel construction on the hydrogeological regime and development of a groundwater monitoring program to be used to assess impacts during pilot tunnel construction.