Time-Varying Reliability Analysis Of Rock Slope Anchorage System And Computational Method

In recent years, With the launching of the western construction of major hydropower projects, more importance has been attached to the stability analysis of high rock slope and the research of reinforcement measures. The anchor rod has the advantage such as cheap, convenient, fast, easy to construct and so on. As a consequence, more concern and attention will be paid to the reliability analysis and evaluation of anchored slope.Therefore, this paper combines theNational Natural Science Foundation (50878082) and Natural Science Foundation of Hunan Province (09JJ3104), to make a systematic analysis of the various failure modes of rock slope under the Time Dependent Anchoring System through theoretical analysis and numerical simulation.Main research achievements are as follows:(1) Based on Multi-failure models and resistance time-varying of every failure models, shear strength parameters time-varying caused by creep, rock slope single slider sliding anchoring system reliability analysis model is established. Based on Monte-Carlo sampling method, a method to solve failure probability of such slope anchoring system time-varying directly is proposed. Results show that, resistance time-varying of different bolt failure modes and strength parameters time-varying of sliding surface have great impact on anchorage system failure probability. A comparation is made among the ordinary least squares, weighted least squares method with JC method and Monte-Carlo sampling method;(2) Based on Multi-failure models of bolt and resistance time-varying, shear strength time-varying caused by rainfall and a long soak time variability on master weak surface, rock slope dual slider sliding anchoring system reliability analysis model is established.Results show that, without considering the bolt impact on the sliding surface strength parameters.strength parameters time-varying of anchoring system basically have no impact on most critical slip surface inclination of passive slide and best anchor point search results. A comparation is made among the ordinary least squares, weighted least squares method with JC method and Monte-Carlo sampling method;(3) While considering the various failure modes of anchor, corrosion bolt and shear strength parameters time-varying of the sliding surface caused by wet and dry cycles, anchor system time-varying reliability analysis model of rock slope wedge slid is established.Results show that, bolt under different service, loaded conditions, concentrations of corrosion solution; Anchor bolt corrosion has an different impact on time-varying failure probability of that type of slope anchor system; So does wetting and drying cycles (due to the different initial moisture content in rock and soil).