Groundwater-related aspects during the development of deep excavations below the water table: A short review

Abstract

The expected growth of urban areas requires the construction of underground infrastructures, especially for improving transportation and mobility. These new infrastructures are commonly constructed below the water table because they must be deeper than previous underground structures. In addition, many urban areas are located near surface water bodies (i.e., seas, rivers and/or lakes) that induce a shallow water table. The “cut and cover” method combined with dewatering wells is a frequently used procedure under these conditions for the construction of underground infrastructures. The main concerns of this procedure are related to the stability of the excavation bottom, the behavior of the retaining walls and/or the impacts induced by the dewatering actions. These issues must be evaluated, and new solutions must be proposed to improve its weak points. This paper compiles the main publications focused on the construction of underground infrastructures below the water table and in urban areas by using the cut and cover method combined with pumping. This review reveals that, despite many published studies, more research is needed to address some relevant issues such as: (1) the mitigation of dewatering impacts by using artificial recharge, (2) the adaptation of methods for characterizing retaining walls to be used under heterogeneous conditions, (3) the improvement of the prediction of surface settlements produced by pumping, and (4) the consideration of non-Darcy flows in the design of dewatering systems.