坡顶张拉裂缝对边坡稳定性影响  

Influence of tension cracks of slope crest on the stability of slope

作　　者：刘锋[1,2] 芮勇勤[1] 张春[3] 

机构地区：[1]长沙理工大学交通运输工程学院,湖南长沙410004 [2]中南林业科技大学土木工程与力学学院,湖南长沙410075 [3]金属矿山安全与健康国家重点实验室,安徽马鞍山243000

出　　处：《辽宁工程技术大学学报（自然科学版）》2016年第9期949-954,共6页Journal of Liaoning Technical University (Natural Science)

摘　　要：为研究竖向张拉裂缝对边坡稳定性的影响,采用极限分析上限法,并考虑稳定渗流场作用,基于边坡的对数螺旋破坏机制,构建了含垂直张拉裂缝的破坏模式,推导了边坡临界高度和安全系数的计算公式.将计算结果与已有未考虑张拉裂缝的极限分析计算结果和极限平衡法的计算结果进行对比.并通过算例分析,研究了孔隙水压力系数变化和抗剪强度参数变化对边坡稳定性以及张拉裂缝临界深度的影响.结果表明:采用的破坏模式是合理的,张拉裂缝的存在降低了边坡的稳定性.强度参数增大提高了边坡的安全性,但随着孔隙水压力的增大,内摩擦角的增大对边坡安全系数增大的影响程度降低,而粘聚力的影响则变化不大;裂缝临界深度随着粘聚力和内摩擦角的增大而增大.The influence of vertical tension cracks on stability of slope is researched using limit analysis upper bound method with the consideration of stable seepage field. The rotational failure mechanism with vertical tension is constructed and based on which the calculating formulas of critical height and safety factor of slope are conducted. Computed results are compared with the ones without the consideration of the tensile fracture by limit analysis method and limit equilibrium method and the influences of pore water pressure and shear strength parameters on the critical height of tension cracks and stability of slope through a practical example. The results shows that failure mechanism adopted by this paper is reasonable and the existence of tension cracks reduce the safety performance of slope. The safety performance of slope increases with the increase of the strength parameters, however, the impact of the increase of internal friction angle to the increase of safety factor gets smaller with the increase of pore water pressure. And there is little impact of the cohesive force to the safety factor and the critical depth of the cracks increases with the increase of cohesion and inner friction angle.

关 键 词：土质边坡 张拉裂缝 极限分析 强度折减 安全系数 

分 类 号：TU432[建筑科学—岩土工程]