Geoelectrical imaging for site investigation for urban underground infrastructure: a TRUST-project

Unforeseen ground conditions are risk factors often leading to delays and significant additional costs in conjunction with underground infrastructure construction work. There are two main geological hazards that are important to identify, manage, or possibly avoid, for safe and efficient underground construction. The first is unstable rock and the second is large groundwater inflow. The latter exists in most underground projects. Other problems are related to human activities such as waste deposits, industrial activities, handling of chemicals and underground activities such as mining and pumping of water. On old landfills and industrial sites, the market value of real estate often increases as cities expand leading to an interest in development. These old and often abandoned areas (former chemical industry, gasworks, impregnation plants, chemical cleaning etc.) are often associated with highly con-taminated soil and soil water.