Foundation Pit Leakage Detection Method Based on Electrical Resistivity Imaging Technology

With the continuous development of city construction and development of underground engineering, increasingly large scale, all kinds of super large and deep foundation pit appear constantly, especially in soft soil and high groundwater level area. Due to the leakage problem of the foundation pit engineering, accidents happen. Pit leakage is a common construction defect of construction waterproof curtain, therefore, it is necessary to detect the leakage situation of the foundation pit supporting system in advance, so that the leakage area is treated and prevented in time. In the foundation pit engineering, it is often used to observe the water level changes inside and outside the foundation pit to deduce the approximate area of the foundation pit leakage. Therefore, the use of geophysical methods for leakage detection research has become a breakthrough in solving the problem of leakage of foundation pit. In this paper, variation of groundwater flow around the foundation pit line is discussed when there is leakage of foundation pit system, for instance, leaking water aggregation, intensive regional seepage resistance, resulting in low resistivity of leakage area around the foundation pit of low resistivity. Based on the resistivity imaging technique, the method for detecting the leakage of the foundation pit by detecting the change of resistivity of soil around foundation pit before and after dewatering is presented. It is through two engineering examples show that this method can detect the pit leakage detection results of three-dimensional position, detection results objectively and accurately.