Failure analysis of water gushing in excavation and application of rapid dewatering and recharge emergency measures

Abstract

The occurrence of water gushing in excavation engineering projects in soft soil areas has caused significant economic losses and adverse impacts. However, there is a lack of rapid emergency response methods for handling water gushing in excavation and conventional methods that are employed to resolve accidents, such as applying grouting to seal water gushing points and engaging counterpressure measures, are often unsatisfactory. Although well dewatering can quickly achieve an emergency response, such wells often cannot be constructed in a timely manner due to the limitations of drilling speed and dewatering often lead to excessive settlement. In this study, a failure analysis of a water gushing accident in excavation engineering in Tianjin, China, is presented, and a rapid dewatering combining recharge emergency measure is proposed to conduct emergency response work for water gushing and other leakage accidents. The mechanism and effect of this emergency measure on controlling water gushing are investigated via numerical simulations. In addition, a rapid well drilling technology was developed that can significantly expedite the construction of dewatering and recharge wells during emergency responses. It is demonstrated that promptly reducing the groundwater level in the confined aquifer near the water gushing point can provide effective disaster control. When groundwater recharge is applied, the settlement of adjacent buildings due to dewatering can be mitigated. With rapid well drilling technology, dewatering combining recharge emergency measure can quickly control the water gushing and leakage accidents in deep excavation and underground engineering, while avoiding large-scale impacts on the surrounding environment.