Research On Work Mechanism And Design Of Composite Soil Nailing

Soil nailing is a new kind of retaining method and it is used widely after it appeared in China for its advantages. The soil intensity is very low and the groundwater level is usually very high in the area of soft soil, so the traditional soil nailing method can't be used in such place. It is the reason why the cemented-soil wall composite soil nail method was invented.The resisting slip mechanism of nail and cemented-soil wall is researched on and the theory of the mechanism is also introduced in this paper firstly.Kinds of working capability such as distribution rule of the internal force of soil nail and the soil pressure in soil and the limit height and the deformation rule of composite soil nail system are all researched on in this paper.The design program and kinds of internal stability analysis of composite soil nailing are introduced in this paper. And on the basis of many literatures, the Bishop method for internal stability analysis of composite soil nailing is presented.A computer program named TDYC.C is designed to calculate the internal stability safe factor. It can also be used for optimum design of composite soil nailing system. Soil nail length and downwards angle can be designed automatically by the program. In addition, the difference between soil nailing and composite soil nailing is analyzed in this paper and some useful conclusions and suggestion are made, which can be used as a reference in real project.A kind of back inference model based on soil pressure for composite soil nailing is presented at last.