Analysis Of Application Research On Slope Stability Based On A Continuum-Discrete Coupling Method

In engineering construction process, the stability of rock mass is the foundation of the other structural stability. The destruction of rock mass macroscopic instability are the result of the development of mesoscopic structure accumulated deformation, for such problems, the traditional analysis conducting the continuum model of finite element or finite difference algorithm can no long satisfy the needs on mesoscopic mechanics perspective of geotechnical structure deformation analysis any more. How to adopt a more scientific method to evaluate the stability of rock mass and ensure the smooth construction of the construction safety are major technical problems need to be solved in academics and geotechnical engineering.Continuum-discrete coupling algorithm is a kind of geotechnical engineering numerical simulation method, by using computer data interface and transmitting the data of force and velocity between the continuous and discrete element software, the macroscopic and mesoscopic calculation results can be calculated synchronously. This method not only can make use of the advantage of convenient modeling and rapid calculation of continuous model for large geotechnical engineering, but can avoid the disadvantage of calculation time too long in a lot of discrete particle model. At present, the further development of continuum-discrete coupling algorithm and the algorithm research from macro-meso perspective collaboratively analysis of the stress and deformation method of rock mass, has become a hot research topic in geotechnical engineering.Based on the continuum-discrete coupling numerical method, soil slope structure as the research object, combined with strength reduction and effective stress theory, from the key step in the continuous and discrete coupling detailed research, this paper use of theoretical analysis, numerical simulation, monitoring and other technical means, comprehensively. And more, combined with the similar large indoor test results to evaluate methods and research the application of the continuum-discrete coupling in the rock mass stability analysis. The main research results include:(1) Through the analysis of existing macro and meso parameters correlation and the research contents of matching, by means of discrete element biaxial load numerical experiments, combining with macroscopic shear strength calibration (stress Mohr circle envelope) and material constitutive features standard (stress-strain curve) parameter debugging method in both of some disadvantages, based on the parameter classification, the analysis of the mesoscopic parameters one by one, according to set initial value assumption and experience, and summarizing regularity in the relationship of the single parameter changes and multiple parameter change on the influence of the macro shear strength. In the end, through multi-factor orthogonal experiment method and the optimization of the calculation results, reasonable macro mesoscopic parameters matching scheme has been obtained.(2) The coupling region of the continuum-discrete coupling numerical simulation method is the foundation of the macro-meso analysis synergistically. According to the significance of the selection of coupling area is important for its using and in the case of the different types of slope coupling characteristics of regional selection, combing with macroscopic shear strain increment and mesoscopic contact force, displacement and failure mechanism in in the process of excavation and loading of the slope, the continuum-discrete coupling model of the selection method of discrete coupling field from the rock mass deformation rate, stress and displacement characteristics are studied, and also defined the reliable selection basis on the position and size of the coupling region.(3) Based on the continuum-discrete coupling algorithm generality and slope applicability for the original command flow to carry on the secondary development, a series of optimization research have been carried out in the caller of the continuous element mesh unit coupling region and the fishtank coupling module and construction of slope continuum-discrete coupling model, which are not only redefined the continuous and discrete domains data transmission boundary, but also laid a foundation of randomly selected for the coupling area and slope structure of continuum-discrete macro-mesos coupling model step deformation monitoring methods of collaborative analysis.(4) Based on the strength reduction theory, the continuum-discrete coupling numerical simulation is adopted to analysis of sub-soil weathering rock slope, from the perspectives of the consistency of macro-meso slope displacement change, the relationship between the shear strain increment and the direction of displacement change, the correlation of slope deformation area and the fracture number change, and the relevance of displacement of macroscopic and the major direction of mesoscopic contact force, have shown that the continuous and discrete effective application in rock and soil slope stability analysis, and from the perspective of macro mesoscopic synergistically analyzing the internal mechanism of the rock mass stress deformation.(5) The indoor similar test of large tailings dam is built, and a large number of test data collection and research is conducted to analysis of the stability of the slope in the condition of water. The size and materials of tailings dam laboratory test are all come from the tailings site and are applied with the stacking load simulation in different mode, different loading rate simulating heap load rate, thereby the water pressure, earth pressure, water level, and the displacement of soil deformation monitoring data are achieved. A similar analysis model with discrete material and water condition is built to analysis of instability mechanism of tailings dam in water saturated state effectively.(6) On the basis of indoor test geometric model, based on the principle of effective stress and introduced floating severe parameters, the continuum-discrete coupled numerical model is set up. According to the seepage line characteristics of tailings dam. adopting unsaturated and saturated soil parameters on the up and down of the seepage line to conduct an macro-meso collaborative analysis under the action of hydrostatic and the continuum-discrete coupling numerical analysis method is verified in aqueous effectiveness of tailings dam stability analysis. Furthermore, combined with Shanxi XiangFen tailings dam failure case, by simulating the dam body load and the prototype of instability, comparing the results of displacement and plastic deformation of stress and seepage coupling model, and from the aspects of the relationship between mesoscopic contact force and displacement of macroscopic and the correlation the contact force chains and contact force component to conduct a reasonable explanation on the instability of large tailings dam and the cause of it.