Research On Lower Bound Method Of Plastic Limit Analysis Of Rocky Slope

Slope stability analysis is an old and complex issue. The qualitative analysis of slope stability is taken as one of the three classic issues of mechanics. With rapid the development of economy in China, an increasing number of railway, highway and tall buildings are being constructed, and mining operations are of a higher frequency, in which the issue of slope stability is involved. Plus, the geographical conditions in China is quite complicated with the high frequency of various landslides happening in central and western China where there are many mountains and hills. The stability of slope is thus an issue concerning national economy and the people’s livelihood. As a result, the improvement of analyzing capacity of the security of slope is of great significance. The character and stability of rocky slope is quite distinct from that of the earthy slope.This thesis bases itself on the analysis and evaluation of slope stability, adopting the block element discretization technique and mathematical programming method to explore the slope stability of therockyslop system by endeavoring to apply lower boundary of plastic limit analysis method into the research in order to resolve the typical issue of rocky slope stability analysis. This thesis mainly focuses on the following aspects:(1) the significance of the study of rocky slope stability is explained and several common methods for analyzing slope stability are compared. In addition, the emergence and evaluation of plastic limit analysis method are introduced and lower boundary of plastic limit analysis method is listed.(2) the simulation of the anchor force of slope compose the important content of slope stability analysis. This thesis first elaborate the function mechanism and influence of the anchor force of the anchor rod on rocky slope. Then, the simulation methods of anchor force in rocky slope are displayed. On the basis of plastic limit analysis, the model of the plastic limit analysis of anchor force are set up and applied to the stability analysis of wedge-shaped rocky slope.(3) the earthquake inertia force is one of the most important factors in damaging rocky slope. This thesis analyzes the damaging mechanism of earthquake force on the slope stability, puts forward the approach to simultating the earthquake inertia force in rocky slope analysis and set up a plastic analysis model under the earthquake force. Plus, the double-slider diffset and multi-slider diffset are analyzed and the calculating results are compared with those worked out by the finite difference method simultation.(4) underground water is one of the key influencing factors on the stability of rocky slope. This thesis first explains the function mechanism of the pore water pressure on rocky slope and then brings up the simultation method for analyzing pore water in rocky slope. On such basis, the boundary mathmetical model of block plastic limit analysis under the pore water is set up. Further, the double-slider and tri-slider diffsets are analyzed by lower boundary analysis on the basis of the finite elements simultation of the rocky slope sepage field. Finally, the calculating results are compared with those worked out by the limit equilibrium method.(5) the problems existing in the plastic limit analysis of rocky slope are summarised and prospected.