膨胀土路堑开挖的力学响应及综合处治技术研究

【作者】 黄建华；

【导师】 方理刚； 陈丰；

【作者基本信息】 中南大学 ， 建筑与土木工程， 2011， 硕士

【摘要】 膨胀土是一种特殊土,具有超固结性,裂隙性和胀缩性的特性,膨胀土路堑滑坡问题一直是公路建设中的难题之一。膨胀土路堑在开挖初期一般比较稳定,在经历干湿循环之后没有处理的边坡往往会发生失稳破坏,掌握滑坡发生的过程和机理,对于边坡加固措施的设计具有重要的指导意义。论文以南(宁)百(色)高速公路膨胀土路堑边坡为研究对象,在对膨胀土路段进行原位试验和室内试验研究的基础上,掌握了南百路膨胀土的成因类型和基本物理力学参数；鉴于常规的极限平衡法只能对坡体的整体稳定性进行分析,利用有限差分软件FLAC研究了膨胀土路堑开挖过程中应力、应变、位移的变化规律,探讨边坡随开挖而渐进破坏的规律,同时研究了干湿循环对膨胀土路堑的影响,分析干湿循环后路堑失稳的原因,为治理膨胀土滑坡提供了理论依据；南百高速公路部分路堑由于开挖后没有采取及时的防护措施,经历干湿循环之后发生了不少的滑坡灾害,针对路堑发生的滑坡灾害,对全线路堑边坡均进行了动态的防治措施,采取了坡面防护、表水防护、支挡结构等多种措施结合来处治膨胀土边坡,收到了良好的效果。更多还原

【Abstract】 Expansive soil is one kind of special clay, which has over consolidated, fracture and swell-shrinking characteristics. Expansive soil cutting landslide has always been a difficult problem in highway construction. Expansive soil cutting is stable in the early excavation, but after cyclic dry-wet process the slope which is not addressed of fern instability failure. We must understand the process and mechanism of landslide, which has important directive significance to the design of slope reinforcement measures.This article takes expansive soil cutting slope in Nanning to Baise expressway as the research object, based on the expansive soil sections in-situ test and laboratory test experiment, we master the genetic type and basic physical and mechanical parameters of nan-bai soil. In view of the conventional limit equilibrium method only can solve the overall stability of the slope analysis, this article use finite difference software FLAC research the change of stress, strain, displacement in the expansive soil cutting excavation process. As times we study progressive failure of slope excavation and wet and dry cutting cycle on the effects of expansive soil, analysis of wet and dry cycles posterior instability of cutting the reasons for the treatment of expansive soils provides a theoretical basis for landslide. Because of a part of the cutting excavation of Nan-bai expressway did not take timely protective measures, after wet and dry cycles occur a lot of landslide. According to this situation, we carried out dynamic control measures which include slope protection, surface water protection and retaining structures to protect slope and have received the good result.更多还原