The Research On The Calculation Methods Of The Shear Strength Parameters Of Jointed Rock Mass And Application In Engineering

As China’s economy and society sustained continuous, rapid and healthy development and the continuous implementation of the great western development strategy, in China, especially in the west and the southwest area of China, rock mechanics problem involved in the infrastructure construction is more and more, investment is becoming stronger and stronger, at the same time, academic circles have not yet prepared for solving the numerous problems in the rock mechanics and engineering, such as how to reasonably consider the influence of the joints and fissures to the mechanical properties of the jointed rock mass etc, there are still a lot of issues that we need to study on. Many times of accidents occurred at home and abroad because of no considering the influence of joints and fissures to the mechanical properties of the jointed rock mass show that it is urgent for studying the properties of the jointed rock mass, and using the technologies for solving the engineering problems.The introduction of contemporary computational mechanics has brought many new ideas and tools for the study of rock mechanics, it makes the once impossible to achieve scientific experiments to become realities. The research of the properties of the jointed rock mass is often impossible to be completed by experiments. This paper uses the methods computer simulation to study the influence of the joints and fissures to the mechanical properties of the jointed rock mass, gains the calculation methods for the shear strength parameters of the engineering jointed rock mass, farther more, the anisotropic shear strength parameters are used to program a code to solve practical engineering FEM problems. The main work of this paper is as follows:(1) According to the statistical geometry and mechanical parameters of the jointed rock mass and the Monte-Carlo method, program the FORTRAN code to simulate the sample of the joint net work, according to the assumes of calculating the mechanical persistence ratio of the jointed rock mass, get the persistence ratio parameters, on this basis, get the anisotropic shear strength parameters of the jointed rock mass.(2) Study the needed input parameters used to calculate the mechanical persistence ratio such as the length of the study model, the repeated calculation times in order to get good results, the projection bandwidth, the assumed average normal stress etc, in order to understand how to input these parameters to get good, stable, reliable results. (3) Based on the user defined materials (UMAT) module of the large-scale general purpose finite element method software ABAQUS, programmed the UMAT code based on the corrected anisotropic Mohr-Coulomb yield criterion, makes the application of the anisotropic shear strength parameters in practical engineering possible, established a bridge between them.(4) Applied the above mentioned achievements in the earthquake analysis of the actual jointed rock slope engineering, verified the feasibility and practical significance of the program and the results above.