膨胀土路堑边坡的破坏型式和稳定性  

Classification of expansive clay slope on road cutting

作　　者：王文生[1] 谢永利[1] 梁军林 

机构地区：[1]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064 [2]广西交通科学研究所,广西南宁530001

出　　处：《长安大学学报（自然科学版）》2005年第1期20-24,共5页Journal of Chang’an University(Natural Science Edition)

基　　金：交通部重点科技项目(95 05 05 13)

摘　　要：基于膨胀土的胀缩性、多裂隙性、超固结性3个基本工程特性的综合分析,将膨胀土路堑 边坡划分为潜伏断面滑坡型、弧面渐进破坏型、浅表层崩塌型3种类型破坏模式。针对弧面渐进破 坏型膨胀土边坡,提出了可以满足施工初期或设计阶段精度要求的简便稳定性分析方法。该方法 采用简化Bishop力学假定条件下的极限平衡法求解边坡最小稳定系数。参数取值时,充分考虑到 膨胀土边坡的渐进破坏特点而选用土体的动员强度。动员强度由峰值强度与残余强度综合折算得 到。用该方法对广西兴业—六景高速公路一处挖方膨胀土边坡工程实例进行了分析,结果表明,边 坡高度为14.3m,坡率为1∶1.5时,稳定系数为0.91,处于不稳定状态;而坡率为1∶2时,稳定系 数为1.07,处于稳定状态。工程实践证明了该分析方法的可靠性。Based on three fundamental characteristics of expansive clay: swelling and shrinkage characteristic, multiple flaw and over consolidation, three types of collapse model of expansive clay slope are concluded, which are landslide with hidden failure, progressive failure with arc side and surface layer slip.The stability analysis for progressive failure slope with arc side is carried out, which not only can satisfy the requisition for precision in initial construction or design, but also has advantage of simplicity and convenience. This means uses Predigest Bishop Method to seek the least safety factor for slope. Fully considering the progressive failure characteristic of expasive clay slope, the mobilized strength parameters are determined from the peak strength and remains strength through converting calculation.This method is applied to an example, whose height is 14.3 m . When the slope ratio is 1∶1.5, the safety factor is (0.91), the slope is instable.When the slope ratio is 1∶2.0, the safety factor is 1.07, the slope is stable. The engineering practice demonstrates that this stability analysis means is reliable.

关 键 词：道路工程 膨胀土 路堑边坡 破坏型式 动员强度 

分 类 号：U412.221[交通运输工程—道路与铁道工程]