Research On Method For Soil Slope Stability Based On Variation Principle

Finite slice method of slope stability analysis, which based on method of limit equilibrium, is accepted by many engineers because it has explicit meaning and visual physical model and easily acquired engineering parameters. But, it has a common shortcoming that give many predicts for resultants of soil slices and can not satisfy all limiting-equilibrium equations. This is more outstanding to three dimension problem. Because of too many predicts, the results of traditional methods are doubted.A new slope stability analysis method, explicitly satisfying all limiting-equilibrium equations, is presented. To make the problem statically determinate, the variational approach is used. In this approach, the normal stress and the critical slip are got by solving the Euler's equations. The minimum factor of safety for the critical surface is sought and obtained mathematically. A simple numerical routine, which can attain the safety factor for anisotropic soil slope, is compiled. The critical slip surface can be automatically drawn by the computer. The presented examples demonstrate varational method is equivalence to finite slice method of slope stability analysis.Finally, stability of Nuozhadu rubble dam is analysized by use of this paper's method. The paper gives critical slips in different condictions. From the result of computation a conclusion can be drawn that slope design of Nuozhadu rubble dam is reasonable. With respect to two-dimension and three-dimension stability analysis, it is demonstrated that three-dimension stability analysis is more rational and applicable.