oa Shallow Geophysical Methods: Helping to Solve Geotechnical Problems, an Australian Perspective.

In response to the Global Financial Crisis the Australian Government implemented a series of Economic Stimulus Packages designed to provide decisive action to support jobs and insulate the Australian economy from the worst of the global downturn. Part of the packages allocated funding for major infrastructure in the transport, communications, water and energy sectors of the economy. This has seen much development being undertaken throughout the country with many development sites located in urban areas. Although not routinely employed, shallow geophysical methods have played an important role at a number of these development sites throughout Australia where specific geotechnical and geoenvironmental problems have been encountered. This is especially the case at brownfield sites where a mixed history has resulted in unknown subsurface characteristics having a potential negative impact on the structures being built above it. Geophysical techniques including electro-magnetics, resistivity, ground penetrating radar, and seismic refraction and surface wave methods have been successfully applied at such sites providing valuable subsurface Information in addressing potential problems before they occur. This paper will present a number of case studies at development sites throughout Australia detailing how various shallow geophysical techniques have been applied and helped to manage potential problems encountered at these sites. Case studies presented include transport infrastructure projects occurring over former landfill sites, where a multi-technique approach to geophysical Investigations have provided subsurface Information critical to the design and construction of the project. This paper will show that whilst playing a niche role, geophysical Investigations are cost effective and can provide valuable subsurface Information at development sites where geotechnical and geoenvironmental problems occur.