Modeling Of Bolt Elements And Simulation Method Study In 3D-FSM Of Indirect Bem

In recent years, bolts are commonly used in the field of geotechnical engineering supporting system. Bolting system has many advantages, such as special results, simple technology and low cost. But quantification of bolt supporting effects is very difficult to confirm. FEM (Finite Element Method and BEM (Boundary Element Method) are two main kinds of numerical methods used in the field of geotechnical engineering. FEM has developed much more completely than BEM, but BEM is much superior in some fields. The existing indirect BEM called 3D-FSM system can't solve the problem with bolt elements. Based on this problem, coupling functions of bolt elements with 3D-FSM system is studied.On the basis of existing 3D-FSM system, bolting system is added, and full-length bonding bolts are adopted. According to the characteristics of bolt supporting system, a hypothesis is conducted that bolt elements are some simple line elements. Analytic solutions of influence coefficients of borehole elements on other elements are deduced. Methods of elastic mechanics and material mechanics are used to solve bolt elements, and the two analytic results have been compared with each other. Material mechanics is also used to solve axial displacements of bolt elements. Bolt elements are coupling with existing 3D-FSM in theory, and corresponding calculating formulations used to form numerical simulation system are deduced.