English：

A deep foundation excavation project in Zhangjiajie City, Hunan Province, is faced with acomplex surrounding environment and geological conditions. The buildings around the foundationexcavation are dense and close. After the foundation excavation support construction is completed, due tothe problem of basement parking space planning, the fourth layer of basement is added to form a “pit inthe pit. ” The main stratum is the high groundwater level boulder stratum. In the pile foundationconstruction, it is difficult to form holes and the jet grouting waterproof curtain. Therefore, it isparticularly important to select the appropriate supporting structure and adopt the appropriate jet groutingwaterproof curtain construction technology. The safety and stability of the foundation excavation andadjacent buildings ( structures) during construction and subsequent use are guaranteed through strictmonitoring and measurement, information construction, and other key technical measures.