Application of a Multi-level Support System in Deep Foundation Pit of Bridge Pier

The construction work platform of Wuhan Xinhe Bridge Pier 11 is small in size. The soil pressure and water pressure next to the foundation pit are unevenly distributed and the strength of the soil is low. In order to reserve a certain space for the foundation pit support and bridge pier construction, the technologies of a variety of foundation pit support design schemes are compared. According to local conditions, a double-row steel sheet pile is adopted combined with soil filling between the piles to form a cofferdam externally; the transition zone in the middle is reinforced by high-pressure jet grouting piles to form a construction road; a multi-level support system for deep foundation pits supported by double-row piles and three steel pipes is adopted inside.Through the collaborative calculation module for three-dimensional calculations and Plaxis 2D finite element calculation and analysis, it is found that this transition system can strengthen the soft soil and play a good deformation control effect. Combined with the results of the pile displacement monitoring, the superiority of the multi-level support system is proved. This system can reduce the force of the internal support, reduce the deformation of the soft soil, and solve the construction in the soft soil area of the riverside with heavy equipment. The problem of insufficient space can also provide a reference case for similar projects.