Stability Analysis For High Fill Slope Under The Reinforcement Of Prestressed Anchor Cable

Prestressed anchorage technique which has much advantages such as reasonable structure, dexterous craft, low cost, convenient construction and high reliability is a kind of advanced technology of rock and soil reinforcement, so it has been highly appreciated by all walks of life and developed quickly. Although the technology is applied widely, it is not yet mature and has many defects:theoretical and numerical analysis of this technology is carried out generally under the ideal situation, and its results are largely different from the actual projects.We still lack unified understanding of mechanism of prestressed anchor cable reinforcement, the application and research of anchorage technique in the slope engineering mainly concentrated in the cut slope reinforcement protection, but there is very little research about the prestressed anchorage technology applied to the high fill slope.Based on a project of one highway, I combined with theoretical analysis and numerical simulation to analyze stability of high fill slope under the reinforcement of prestressed anchor cable. First I used the limit equilibrium method to make estimation of stability, and got results of optimal arrangement of anchor cable, anchor length, anchor force and the anchorage angle;Then I used PLAXIS which is finite element analysis software to make a feasibility analysis of anchor cable reinforcement methods, and simulated reinforcements of the pile, the tensile anchor and the pressure anchor,analyzed changes of displacement and safety coefficient,as a result tensile type of prestressed anchor is the most economic and effective way of strengthening. Finally I analyzed slope stability under natural and rainfall conditions:changes of axial force on free end and the anchor end from slope sedimentation,changes of pull stress.compressive stress and shear stress of soil which around inside and outside of the anchor end, changes in displacement and safety in two situation which before and after anchoring and the overall safety coefficient of slope.The results show that prestressed anchor can improve the strength of soil,and make soil around the internal and external anchor end form a concentration area of the stress.beyond that,prestressed anchor reduces displacement changes and improves the stability of slope.at the same time.the sedimentation of slope increases the axial force on free end and the anchor end. Rainfall reduces the shear strength of soil mass and has a huge impact on slope stability.The results can provide theoretical guiding significance for reinforcement projects of high fill slope in the future.