Study Of Dynamic Design Technique & Simulation Of Soil Nailing In Deep Excavation

Soil nailing, a new retaining system in deep excavation, is more and more widely used in our country. It's a kind of economic, reliable technology and is convenient in construction. But at present, the method of soil nail design is not perfect, and the theory lags behind the application in the engineering practice.Based on the past researches, the theory of dynamic design of deep excavation retained with soil nail is provided in this paper, in the consideration of that the soil nail retaining system is a dynamic procedure of the interaction of structure and soil. To the problem that there is a difference between the soil nail forces calculated in National code and measured in practice, using the preferred plane theory, an incremental calculation method for soil nail forces based on preferred plane theory is given.The results indicate that the soil nail forces calculated in this method can fit the engineering practice better. Taking advantage of software ANSYS, the paper analyses the soil nailing with 3D nonlinear FEM.Using theories in Soil Mechanics and results got from an engineering practice, the incremental calculation method for soil nail forces given in this paper is proved. Based on the results of numerical simulation, some conclusions are gotten: (1) the law of soil nail forces in whole-length of nails, (2) the law of soil nail forces' varivation in different depths, (3) the position of soil nail with the largest force, (4) the position of the largest soil nail forces in different depths; and some brief explanations are given to these conclusions.