Abstract: To protect the groundwater resources and prevent the impact of the dewatering inside the excavated area on the surrounding environment, most the deep excavation support projects need to setup the groundwater stop curtains, which are mainly in the form of cement mixed soil system, such as soil-cement mixed columns; jet grouting columns, etc. The groundwater curtain stopping leakage is the main hazardous source of deep excavation projects, which will have a great impact on the project and the surrounding environment. Combined with the leakage hazards of a deep excavation project, this paper focuses on the plugging method and the implementation effect adopted in the mitigation process of the excavation. Facts have proved that for the minor seepage of the groundwater stop curtain of the excavation system, the treatment method of “internal drainage and internal plugging” can be adopted; For more serious seepage, the treatment method of “external stopping and internal plugging” should be adopted, and the method of “external stopping” should be selected in accordance with the local conditions to highlight mitigation process.

Key words: Deep Excavation Seepage, Seepage Stopping, Double Liquid Grouting, Jet Grouting, Steel Sheet Pile