Influence of C and F Values on Slope Supporting by Soil Nailing Wall in Thick Miscellaneous Fill Site

In recent years, soil nailing wall supporting technology is widely applied in the design of pit supporting. However, in the design of deep foundation pit supporting in miscellaneous fill site, the values of cohesion and angle of internal friction, that is c and f, are too conservative to be chosen, so the security and economy cannot be obtained together. To study the influence of c and f values on deep foundation pit supporting design in miscellaneous fill site, Lizheng-FSPw60 was the analysis software, and the circular sliding simple slice method was the theory. It is concluded that cohesion and internal friction angle of the soil have great influence on the stability of the soil nailing wall, and if f value changes by 5°C, the amount of reinforcement and cement will change by 50%. Meanwhile, an slope supporting engineering example was designed, in which the thickness of miscellaneous fill was up to 12 m. Analysis and practice show that if c and f values are reasonably chosen, the slope supported by soil nailing wall in thick miscellaneous fill site will be much safer, and the project will be less wasteful.