水力效应对裂缝边坡稳定性影响的上限分析

Upper Bound Analysis of Cracked Slopes Subject to Hydraulic Effect

为了解决地下水位变化对裂缝边坡稳定性的影响,基于极限分析上限法及强度折减技术,将孔隙水压力以外力的形式参与能耗计算,分析了水力效应对裂缝边坡稳定性影响,重点研究了临界裂缝深度和最不利裂缝位置随地下水位、边坡坡角的变化规律.研究结果表明:地下水位、边坡坡角对最不利裂缝位置及临界裂缝深度的影响显著;当地下水位较低时,最不利裂缝随地下水位的增大逐渐靠近坡顶缘;在裂缝位置已知及裂缝深度、位置均未知的情况下,临界裂缝深度受地下水位的影响呈现出不同的规律性.所得成果为研究复杂条件下的边坡坡顶临界裂缝深度及最不利裂缝位置提供了一种新思路.

Ground water level fluctuations have greatly influence on stability of slopes with cracks. Pore- water pressure as the external force was involved in the calculation of energy consumption based on the upper bound limit analysis and strength reduction technique. The effect of pore-water pressure on stability of slopes with cracks was analysed. However, the change rules of critical depth or position of cracks under the effect of ground water level and slope angle was the focus of this paper. Results show that the critical position and depth of cracks significantly depend on the ground water level and slope angle. The increase in ground water level makes the critical crack close to slope crest in the case that ground water level is low. It is also observed that the influence of ground water level on critical depth of cracks presents different regularity for the case of crack position known and both crack position and depth unknown. Research results provide a new method for obtaining critical crack located on the upper surface of slopes under the complex condition.