Assessment of settlements caused by groundwater control

Lowering of groundwater levels by pumping increases vertical effective stress in the soil around an excavation. The resulting ground settlements are normally small, but in certain circumstances may be large enough to cause damage to surrounding structures. This paper describes the mechanism of these settlements and presents a simple risk assessment methodology for initial identification of zones where buildings may be at varying degrees of risk of damage. These risk zones can help to determine the extent of preconstruction building condition surveys needed, or to assess the need for settlement mitigation or avoidance measures. Potential uncertainties in the assessments are discussed.