A Study On Numerical Simulation Of Underground Caves Excavation And Engineering Application

There has been great and rapid progress in underground geotechnical engineering, and it expands and extends the living space of people. People can be able to make better use of the resource. For the future, there will be a long time to go in the underground geotechnical engineering. The research is very difficult, because the analysis and design of the underground geotechnical engineering are extremely complex. There are many uncertain factors to be considered to complete this kind project. Although it has developed for rather a long time, the achievement is limited, and the knowledge is not sufficiently good. Usually, three is much difference between the theory and practice, learned from the real projects. So it is important to study the underground geotechnical engineering for both theory analysis and the practice, and it is much to be perfected.This thesis introduced the numerical method and the development construction process simulation, and then the back analysis development of origin geostatic stress is introduced, followed by the problem in it. Because of limited knowledge, people usually use side pressure coefficient to control the scale of the geostatic stress in the analysis and design. This paper discussed the relationship between side pressure coefficient, the parameter of the material and the stability of the underground rock wall. The conclusion is significant, and it can offer references and guide for the design.Usually, in underground geotechnical engineering two-dimensional analysis is adopted, not three dimensional, because of the special complexity of the caves, the nonlinear material and the nonlinear excavation process. Here, the difference, between two-dimensional and three-dimensional analysis, is particularly studied, and we found that two-dimensional analysis magnified the plastic region. This may induce unnecessary waste, and this may not be safe.D-P yield criteria are based on the Mohr-Coulomb criteria, and fit to rock and soil materials. At present, the study and application of D-P are classical D-P yield criteria, In the meridional plane, classical D-P yield criteria are linear. But the intensity of rock or soil has been testified to be nonlinear at high or low confining pressure. Then, nonlinear D-P is necessary for simulating the properties of some rock or soil materials. Here is a primary discuss about generalized D-P model.With the method and the rule in this paper, a real project is given, analyzed by three-dimensional finite element method. Based on the software, ANSYS, some program isdeveloped with APDL to combine excavation and timbering. PCG is used to solve the linear equations, boosting the ability for morbid equations. With these studies, the numerical analysis went on well, and the result may be referred by the practice.