Numerical study on the stability of limestone bank slopes under the influence of reservoir water fluctuation
Based on field investigation and sampling,the mechanical parameters of limestone and the degradation characteristics of strength under dry-wet cycles were determined by mechanical tests.Through the establishment of a numerical model of the shoreline slope utilizing UDEC,this study examined the process of instability evolution and the impact of weathered zone degradation depth and rock layer thickness on the stability of various shoreline slope types in the Three Gorges Reservoir region.Specifically,the anti-dip bank slope,parallel-layer bank slope,near-horizontal layered bank slope,and shoreline slope containing dangerous rock masses were included in the analysis under the influence of reservoir water level fluctuations.The findings demonstrate that the failure process of the shoreline slope under reservoir water level fluctuations can be categorized into stages of crack initiation,crack propagation,and slope failure.Additionally,an increase in the degradation depth of the weathered zone leads to a decrease in the stability coefficient of the four types of shoreline slopes,while an increase in rock layer thickness results in an increase in their stability coefficient.Of note,the stability coefficient of the near-horizontal layered bank slope is significantly influenced by these factors,and with minimal changes arising from the increase in the number of dry-wet cycles.Subsequently,when the degradation depth exceeds 10 meters and the rock layer thickness surpasses 5 meters,the variation in the stability coefficient of the shoreline slope containing dangerous rock masses due to changes in influencing factors is relatively minor.In the long term,the stability of the four typical rocky shoreline slopes influenced by reservoir water level fluctuations from large to small is:anti-dip bank slope,near-horizontal layered bank slope,parallel-layer bank slope,bank slope containing dangerous rock masses.
hydro-fluctuation belt deteriorationreservoir bank slopenumerical simulationinstability failurerock mass stability
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