The Coulomb Lecture − linking theory and practice in groundwater control

Groundwater control measures are often required when construction excavations are made below groundwater level. A range of techniques are available to avoid or mitigate the effect of uncontrolled groundwater inflows and groundwater pressures. The methods can be grouped by those that deal with groundwater by pumping, by exclusion or by the application of fluid counter pressures. Many of these techniques are long established, with some dating back to the mid-19 th century. Yet despite there being little truly new and innovative about most groundwater control techniques, problems still occur, and groundwater control systems may not perform as originally intended. One possible explanation of these problems is a disconnect or misunderstanding between the theory and practice of groundwater control, as applied to construction projects. This paper will describe the theoretical basis for the design of groundwater control systems and discuss various aspects of successful and unsuccessful practical applications, including conceptual models, the performance range of the available techniques, and selection of appropriate parameter values for design.