The Research Of Stability Analysis Of Rock Slope Based On Finite Element Method Of Stress Integral Residual Thrust Under Each Sliding Plane Having Equal Safety Coefficient

Due to the impacts of geological origin and construction，various joints andfissure, fault or weak interlayer unstable structure surface disappear inslope,which will have a significant impact on the stability of slope. It will lead toserious engineering accidents such as landslide, dumping, if these unstablestructural planes interconnected, well versed in slope rock mass. Once theseaccidents happened, the results of its consequences are unpredictable. If theseweak structural planes have to be deal with, the engineering expense is very largeand difficult to eradicate. So it is a common and important engineering problemon analyzing and accounting anti-sliding stability of rock mass slope.The researchers create a lot of calculation methods, and form a set ofcomplete and mature theory system through actual project verification, since thestudy of anti-sliding stability of rock slope was put forward. However, because ofvarious factors on the stability of rock mass slope have effects that cannot beignored, and the principle in the process of analyzing all these factors cannot befully considered. The current theory of rock mass slope stability analysis have its respective advantages and disadvantages, even to this day, unified standard,objective and accurate evaluation method have not been formed. Therefore, theslope stability problems are necessary to be further discussed.This article analyze the defects of the traditional finite element stress algebrasum calculation method on the rock mass slope stability, put forward residualthrust of finite element method which considering the critical slip surfacedirection angle factors, the safety coefficient calculated by two kinds of methodswas analyzed and compared. Searching for incomplete penetration weakintercalated rock mass slope ultimate failure surface, and trying to find theminimum safety coefficient of critical slip surface (the most dangerous slidingsurface). Concrete research content are as follows:(1) The principle of the finite element stress integral method and train ofthoughts were putted forward, which were referred to as the finite element stressintegral safety coefficient of residual thrust method in this article. The safetyfactor calculated by the method of traditional finite element stress algebraic sumthinking about the ratio of sliding resistance force and sliding force only, theinfluence of angular separation between various slip surfaces are not taken intoaccount, so the result have large deviation with the situation of engineering actualdestruction. The proposed approach in this paper given full consideration to theinfluence of the direction angle. On the premise of equals safety factor, cohesionand friction coefficient of the material played is ci/k，fi/k. Working out the slidingforce and sliding resistance force of various slip surfaces and subtracting one from another, if the result is positive value, we see it as residual sliding force, otherwise,it is sliding resistance force. The safety factor k of critical slip surface can be foundout by establish balance equation of residual sliding force (sliding resistance force)in every slip surface on the main direction of sliding surface.(2) FORTRAN language was introduced in the algorithm of the finiteelement stress integral residual thrust method, which can solve the complexcalculation process with convenient, efficient, fast computer language andbroadened the prospect for the application and promotion of this method.(3) By comparative analyzing safety factors calculated by two kinds ofmethods with example, it shows that the safety factor calculated by residual thrustmethod that consider about the influence of angle factors between slip surfaces,while there are uncertainty and simplicity in traditional stress algebraic summethod. Meanwhile, the fracture plane direction of minimum safety coefficient iscontrary to engineering common phenomenon.(4) In practical engineering, the weak structural planes of rock mass slopesare often incomplete penetration. The critical slip surface direction when rockmass be destroyed eventually become an important subject in this paper. Thispaper mainly analyzed the rock mass slope of incomplete penetration containingtwo weak interlayer, the slope of the most dangerous rupture surface can becalculated by changing the initial rupture point position of sliding surface and theangle between sliding surface and horizontal direction, and used the finite elementresidual thrust method proposed in this paper as a way of solving the safety factor. The sliding surface with minimum safety factor (most dangerous sliding surface)can be found out after a comparative analysis of the calculated safety factor.(5) The residual thrust method of finite element considering the influence ofthe angle between the slip plane factor not only inherited the advantages ofthe finite element stress algebraic sum method that can directly calculate safetyfactor, but also the safety factor is closer to engineering objective reality thantraditional algebra sum method. Searching the final rupture surface from rockslope of non through weak interlayer based on this method is also in line withthe actual engineering. So the study of this method on rock mass play great rolein promoting the development of slope stability.