水泥土桩加固边坡变形破坏特性及模型试验分析  

Analysis of model test and failure of slope reinforced by soil-cement pile

作　　者：许胜才[1,2] 张信贵 马福荣[1,2] 陈子兴[1,2] 

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004

出　　处：《岩土力学》2017年第11期3187-3196,共10页Rock and Soil Mechanics

基　　金：广西防灾减灾与工程安全重点实验室开放课题(No.2012ZDK08);广西重点实验室系统性研究项目(No.2013ZDX11);国家自然科学基金项目(No.51268003)~~

摘　　要：水泥土桩是软土边坡常用的一种较经济的加固结构,但目前对水泥土桩加固边坡的变形破坏特性和抗滑机制认识不清,相应的稳定性评价理论研究较少。建立了一边坡模型,运用有限元分析了离散水泥土桩加固边坡的变形破坏特性,结果发现边坡失稳时,桩-土之间由于变形不协调而产生塑性滑移,强度和刚度都较大的水泥土桩呈S型挠曲变形而发生弯折破坏,未能有效发挥设计要求的抗滑能力,加固边坡最后形成贯通的剪切滑动带而非滑动面。提出了水泥土剪力墙的概念,通过有限元模拟发现,采用水泥土剪力墙加固边坡,因墙-土界面摩擦力的作用,下滑力在剪力墙和边坡滑体之间得到调整,最终促使加固边坡产生整体剪切破坏,有效发挥了剪力墙的抗滑能力。通过桩土复合结构的水平推剪模型试验,验证了数值模拟结果的合理性。Soil-cement pile is a common cost-effective reinforced structure used in soft soil slope. However, its deformation, failure, and mechanism of anti-sliding to improve the slope still remain unclear. Currently, relevant researches on stability analysis are relatively limited. A slope model was established by finite element method to analyze the deformation and failure characteristics of reinforced discrete cement-soil pile. The results show that, when failure occurs, the deformation incompatibility between the pile and soil would cause plastic sliding. The soil-cement pile with large stiffness and strength deflects into S-shape, leading to a bending failure of soil-cement pile. It indicates that the soil-cement pile fails to develop the slide-resistant ability as design required. Finally, a shear slip band, instead of a slip surface, passed through the stabilized slope. A concept about soil-cement shear wall has been proposed. By the finite element simulation, the sliding force was found between the shear wall and slide mass due to the effect of interface friction when the soil-cement shear wall was used to stabilize the slope. The general shear failure would occur in the stabilized slope, meaning that the shear wall has effectively mobilized its slide-resistant capacity. At last, a lateral shear model test on the pile-soil composite structure has been carried out to verify the results of the numerical simulation.

关 键 词：水泥土桩 水泥土剪力墙 安全系数 强度折减法 模型试验 

分 类 号：TU443[建筑科学—岩土工程]