Abstract

Groundwater is a common problem in excavations associated with basements, foundations and tunnels. If not adequately controlled and managed during construction, groundwater can cause a range of geotechnical problems, including running sands, excessive ground loss, base heave and collapse of excavations, resulting in additional costs and time delays. However, with good planning, design and execution, below ground works can be successfully and efficiently carried out even in very challenging groundwater conditions. This presentation provides a background to the more commonly used methods of groundwater control and dewatering, and includes a review of the techniques used for groundwater control by pumping (sump pumping, wellpoints, deep wells, ejector wells) and for groundwater control by exclusion (cut-off walls, grouting, artificial ground freezing). Particular applications and challenges of groundwater control are discussed.