深基坑土钉支护机理的现场测试及三维数值模拟研究

Soil nailing is a sort of new support system developed in recent year, and it has already been extensive application in the supporting system of deep-foundation pit . Based on the in situ measured data of hairun mansion deep-foundation pit excavation in Beijing, which include steel bar stress and lateral deformation, the following categories are systematically studied: (1) Magnitude of lateral deformation and displacement distribution vary with time at different excavation depth of deep-foundation pit excavation. Magnitude and distribution of soil nailing force vary with time at different excavation depth of deep-foundation pit excavation. By contract with the in situ measured data, we process the three-dimension numerical simulation of deep-foundation pit excavation with soil nailing support by Fast Lagrangian Analysis of Continua 3D(FLAC~(3D)). By above in situ measurement and studying, we found that the mechanism of soil nailing support is: by stress sharing, stress transmission and diffusion, and displacement restriction, composite soil nailing system can improve the strength and rigidity of soil and decrease the deformation and failure state by enhancing the whole stability of slope.