考虑拉裂缝的斜坡软弱地基路堤稳定性分析  

Stability Analysis of Embankment over Sloped Weak Ground Considering Tension Crack

作　　者：蒋鑫[1,2,3] 梁雪娇[1,2,3] 刘红坡[1,2,3] 姜春亮 邱延峻[1,2,3] JIANG Xin;LIANG Xuejiao;LIU Hongpo;JIANG Chunliang;QIU Yanjun(School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China;Highway Engineering Key Laboratory of Sichuan Province, Southwest Jiaotong University, Chengdu 610031, China;Key Laboratory of High speed Railway Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学道路工程四川省重点实验室,四川成都610031 [3]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031

出　　处：《铁道学报》2018年第5期109-115,共7页Journal of the China Railway Society

基　　金：国家自然科学基金(51378440);国家重点基础研究发展计划(973计划)(2013CB036204);中央高校基本科研业务费(SWJTU12CX067);西南交通大学研究生创新实验实践项目(YC201501110)

摘　　要：评述斜坡软弱地基路堤稳定性研究面临的挑战性,应用极限平衡法软件Slide、有限元法软件Phase2,分别从推力线分布状况、达到临界剪切强度折减时单元拉伸屈服分布状况角度出发,探讨斜坡软弱地基路堤稳定性分析中引入拉裂缝的必要性;在极限平衡法基础上,利用敏感性分析法确定拉裂缝分别在干燥和完全充水条件下的最不利深度;分析拉裂缝引入后对稳定安全系数、最危险滑面形态及条间法向力的影响,阐述拉裂缝水分充填对稳定性的不利作用。研究结果表明,敏感性分析法可较好地确定拉裂缝的深度;考虑拉裂缝后,滑块土条条间法向拉力消失,稳定安全系数降低,设计更趋于安全,拉裂缝完全充水将进一步加剧斜坡软弱地基路堤稳定安全系数的降低;滑面由上部垂线和下部圆弧共同组成,其形态更真实客观。The challenges in the stability analysis of embankment over sloped weak ground were discussed.Based on the limit equilibrium method software Slide and finite element method software Phase2,the necessity of considering tension crack was discussed in the stability analysis of the embankment over sloped weak ground from the perspective of thrust line distribution and the zone of tension failure at the critical shear strength reduction factor.Based on the limit equilibrium method,the sensitivity analysis was used to determine the worst tension crack depth under dry and water filled conditions.The effects on stability safety factor,global minimum slip surface and inter-slice normal force after the introduction of tension cracks were deliberated while the adverse effect of water filled tension crack on the stability was expounded.The results showed that the sensitivity analysis method can better determine the tension crack depth.As a result of the consideration of tension crack,the inter-slice normal tensile force vanished.The lower factor of safety led to safer design.The filled water in tension crack can exacerbate the decrease of stability safety factor of embankment over sloped weak ground.The slip surface,in more real and objective shape,consisted of upper vertical surface and bottom circular surface.

关 键 词：斜坡软弱地基路堤 稳定性 拉裂缝 敏感性分析 极限平衡法 

分 类 号：U416.1[交通运输工程—道路与铁道工程]