考虑滑体法向应力突变的阻滑桩成拱效应研究  

SOIL ARCHING EFFECT AMONG ANTI-SLIDE PILES WITH CONSIDERATION OF NORMAL STRESS MUTABILITY IN SLIDING MASS

作　　者：董捷[1] 张永兴[1] 吴汉辉[1,2] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆蜀通岩土工程有限公司,重庆410047

出　　处：《地质与勘探》2008年第6期97-102,共6页Geology and Exploration

基　　金：国家自然科学基金(编号:50878218);国家杰出青年科学基金“岩土工程减灾”(编号:50625824);三峡库区三期地质灾害防治高切坡防护工程科研项目(编号:2008SXG02-2)共同资助

摘　　要：依据阻滑桩的受力特点,研究了桩间土拱效应的传力机理,分析指出桩间土拱效应是法向应力和拱脚剪切力共同作用而产生的土颗粒挤压变形现象,提出采用突变效应替代常用的桩-土承载比衡量桩间土拱效应的强度及作用范围更为直接可靠。模型桩推力试验结果和三维有限元模型计算表明,桩间水平土拱具一定的纵向效应,据此对比分析了阻滑桩三维与二维计算结果之间的异同,指出桩间土拱效应不仅受桩-土相对位移的影响,同时也受滑体自重应力和滑面摩擦效应的制约。运用二维模型重点研究了桩-土相对位移、桩间净距、推力荷载、土体抗剪强度对桩间土拱效应的影响,将所得规律与已有文献作了进一步地对比,继而总结了上述因素对拱效应的敏感度。Actuating mechanism of soil arching effect is studied among anti slide piles based on their forced characteristic. It is considered that the soil arching effect is a pressing deforming phenomenon of soil mass which is affected by normal stress and arch springing.shear stress. The mutability of should be considered to be substituted for the ratio of loads on pile and soil to ineasure action extent and range of soil arch, which is more directer and reli- able. There is longitudinal effect of horizontal soil arch according to test determination and 3D FEM calculation results. The contrast between 2D and 3D calculations is made to indicate that the extent of soil arch effect is impacted not only by relative displacement between pile and soil but also its geostatic stress and sliding resistance. Several relations between arching effect and some parameters such as relative displacement, clear spacing between adjacent piles, thrust load and shear strength of soil are emphatically researched by establishing 2D FEM. These influence regularities are compared with correlated documents that have been published, and the sensitivities between these parameters above and soil arch effect are finally generalized.

关 键 词：阻滑桩 拱效应 有限元 法向应力 突变 

分 类 号：TU473[建筑科学—结构工程]