Combined recharge: A method to prevent ground settlement induced by redevelopment of recharge wells

Abstract

Artificial recharge is an effective way to minimize dewatering-induced ground settlements in deep excavation. To ensure the success of a long-term recharge, it is necessary to redevelop recharge wells (i.e., pumping) periodically to prevent well clogging. Field measurements show that ground settlements will occur during the well redevelopment. This paper proposed a method referred to as the combined recharge to eliminate settlement during well redevelopment. In the proposed method, a row of recharge wells (AR well) is added at the side of the traditional recharge wells (PR wells) to compensate water loss due to PR well redevelopment. Two field tests (with and without use of combined recharge) are conducted to investigate the ground response to recharge and redevelopment. Test results show that building settlements will increase progressively during redevelopment for case without combined recharge. However, there are no significant surface settlements during redevelopment for the case with combined recharge.