关键词: 软土地层, 竖向MJS工法, 紧邻既有车站, 基坑开挖, 沉降控制

Abstract: The Metro Jet System (MJS) construction method has the advantages of larger column diameter, less disturbance to the surrounding environment and less construction pollution and can be applied in inclined, vertical and horizontal directions. During the construction of the transfer node of the Waitan Bridge Station of Line No. 7 of Ningbo Rail Transit, considering that the new building is close to the existing station in the complex surrounding environment of the soft soil stratum, the construction is likely to cause large deformation and excessive settlement of the project structure and surrounding structures, etc., so the MJS construction method is adopted to strengthen the structure. Throughout the data analysis of monitoring points during the construction, it is found that the soil has a general settlement trend, and the settlement changes faster in the early and later stages of construction. The monitoring points near or far from the excavation have less settlement and even bulge and the maximum appear at about 12m from the excavation. At different monitoring points along the same distance around the excavation, the overall change trend is similar. During the construction period, the maximum accumulated settlement of the excavation is 29.17mm, which meets the deformation control requirements.

Key words: Soft Soils, Vertical MJS Construction Method, Adjacent to Existing Stations, Deep Excavation, Settlement Control