抽水示踪法探测地下连续墙渗漏的试验及数值模拟研究

基坑围护结构的完整性是保证基坑安全开挖的关键，一旦发生渗漏将成为威胁基坑施工的重大隐患。针对地下连续墙渗漏提出抽水示踪探测法,为验证其在实际工程中的适用性，依托苏州市轨道交通8号线虎殿路站基坑工程开展研究。1）在地下连续墙两侧布设钻孔，进行地下水渗漏抽水示踪联合探测； 2）结合天然及抽水状态下的试验数据，对地下连续墙渗漏隐患位置进行研究； 3）建立二维有限元数值模型，对不同渗漏深度下的观测井流速进行模拟，并与实测结果进行对比验证。研究结果证明了抽水示踪法用于地下连续墙渗漏探测的可行性及有效性。

Experimental and Numerical Simulation of Pumping Tracing Method for Detecting Leakage in Underground Diaphragm Wall

The integrity of the foundation pit enclosure structure is key to ensure the safe excavation of the foundation pit. In this study, the pumping tracing method is proposed for detecting underground diaphragm wall leakage, and a case study is conducted on a foundation pit project of Hudian road station on Suzhou railway line 8 to validate its applicability in practical projects. First, a joint leakage detection method of pumping and tracing is applied by placing boreholes on both sides of the underground diaphragm wall. Second, the location of the hidden leakages in the underground diaphragm wall is investigated according to the test data under natural and pumping conditions. Finally, a two dimensional finite element numerical model is established to simulate the observation well flow rate under different seepage depths, and the results are compared with the actual measured results. The study results demonstrate the feasibility and effectiveness of the proposed method in underground diaphragm wall leakage detection.