Recently, the Ningbo Qizha Street Underground Passage Project, contracted by Shanghai Guangda Foundation Engineering Co., Ltd., is under vigorous construction. The project started in early April 2016, with two sets of MJS equipment invested. A filter press is used to compress the replacement slurry generated by MJS construction, and a dedicated dust collector is installed to solve the dust problem, minimizing the impact of construction on the surrounding environment. During the process, the equipment operated stably, and the MJS construction task is expected to be successfully completed by the end of May, creating favorable conditions for the subsequent construction tasks of the project.
　　It is reported that the project is located at Qizha Street, Haishu District, Ningbo City, starting from Zhongshan Road in the south and ending at Heyi Road in the north. The foundation pit is arranged in a "一" shape, with a total length of about 126m from north to south, a standard section net width of about 9.7m, an excavation depth of about 10m, and an excavation depth of about 15.6m at the pit-in-pit. The surrounding environment of the project is extremely complex. The east and west sides are adjacent to Oriental Shopping Center and Xinhualian Shopping Center respectively, and the south side is adjacent to Zhongshan East Road, which is a main east-west arterial road in Ningbo City with busy traffic. Under the road is the open-cut section from Gulou Station to Dongmenkou Station of the first phase of Ningbo Rail Transit Line 1, which is already in operation.
　　The retaining structure adopts hard-bite cast-in-place piles combined with one reinforced concrete strut and four Φ609 steel struts. Within 50m of the Oriental Shopping Center, Xinhualian Shopping Center, and the subway station, MJS piles are installed outside the hard-bite cast-in-place piles as isolation walls to reduce the impact on the surrounding environment during the construction of the bite piles. The nearest distance from the Xinhualian Shopping Center on the east side to the MJS piles is about 5m, and the edge of the Oriental Shopping Center on the west side is only 3m from the edge of the MJS piles. In the MJS construction area, there are many pipelines such as temporary telecommunications, water supply, and power, with the closest distance to the MJS piles being about 0.5m.
　　The MJS piles adopt a 3.6m super-large diameter. The MJS piles on both sides of the Oriental Shopping Center and Xinhualian Shopping Center are semi-circular piles with a length of 21m; the piles near the tunnel section of Metro Line 1 are full-circular piles with lengths of 7m and 12.5m. The strata for pile formation are mainly plain fill, mucky clay, clay, and silty clay interbedded with silty sand.
　　Based on the successful implementation of a series of projects, this method has made new breakthroughs. Its unique technical advantages enable it to be more widely used in foundation treatment and waterproof reinforcement projects for urban public buildings, subways, water conservancy and hydropower, municipal roads, etc., with broad prospects.