Abstract:

The force and displacement laws of supporting system of deep and large foundation pit of North Railway Station of Kunming Rail Transit Line No. 4 is studied by numerical simulation method. The layout and application effect of the support servo system are discussed and analyzed based on field monitoring. The results show that: (1) The reinforced concrete axial force level in the support system is larger than that of the steel support due to the support form and the support spacing, the axial force of support is distributed in a broken line, and the retaining structure is prone to large deformation during concrete support construction. (2) By introducing the supporting axial force servo system and setting the correct axial force value according to the numerical calculation and design requirements, the deformation control effect of the support on the retaining can be better exerted. (3) The engineering application shows that the support axial force servo system has a good application effect in deep and large foundation pits; the cumulative horizontal deformation of the retaining structure in section with servo support is less than that without servo support, which shows better supporting effect.

Key words: foundation pit engineering, support servo system, deformation control, deformation monitoring of underground diaphragm wall