Research On Technology Of The Lssen Steel Sheet Pile In The Excavation Of Deep Foundation Pit And Its Application

As a new type of construction material, Larsen steel sheet pile is wildly used in different type of construction and foundation supporting system. There are different type of application of Larsen steel sheet pile in both temporary buildings and permanent building such as earth-retaining wall, parapet wall, breakwater, temporary extension, water cutout, cofferdam and the retaining of sand, soil and water. Using Larsen steel sheet pile will make sure that the construction is quick, green and low cost. In conclusion, Larsen steel sheet pile is a effective and cheap new construction technique.In the process of the construction of the supporting system in Shanghai Baogang, Larsen steel sheet pile was applied to ensure the successful completion of the excavation and the construction of the structure. In this paper, a series of fundamental research on the supporting method of the Larsen steel sheet pile was carried out according to field test, data monitoring, theoretical calculation and numerical calculation.First, based on the application results of the Larsen steel sheet pile in Shanghai Baogang, the following conclusion can be drawn: The application of Larsen steel sheet pile rose the speed and safety of the construction, and also decreased the space necessary for construction. Compared to other type of supporting form, turnover frequency of Larsen steel sheet pile is bigger, construction cost is lower and construction speed is higher. Moreover, by using the Larsen steel sheet pile influence of the weather on the construction process was decreased significantly, which can rise the reliability of the construction time prediction.Second, according to the analysis of the construction site monitoring data, underground water has a great influence on the construction of Larsen steel sheet pile. Therefore, in the construction of Larsen steel sheet pile in high underground water level area, special attention should paid to prevent quick sand and piping. Furthermore, deformation monitoring of the supporting system and ground settlement monitoring of around the foundation pit in the construction process of the main structure and excavation should be carried out to perform the safety control of the construction process.Finally, a FEM model of the supporting system was established. Stress nephogram and deformation nephogram obtained from the analysis was discussed. Moreover, simulation results and field monitoring results is similar, and the varation pattern is the same, which demonstrating the rationality of the simulation process. Research results can provide reference for the prediction of the deformation and stress of the supporting system in construction process and the application of Larsen steel sheet pile.