桩承式路堤土拱效应简化分析方法  

A simplified method for analyzing soil arching effect in pile-supported embankments

作　　者：费康[1,2] 王军军[1] 陈毅[1] 

机构地区：[1]扬州大学岩土工程研究所,江苏扬州225009 [2]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098

出　　处：《岩土力学》2012年第8期2408-2414,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.50908198);江苏省高校自然科学研究基金(No.09KJB580004);河海大学岩土力学与堤坝工程教育部实验室开放基金(No.GH200805);扬州大学"新世纪人才工程"资助项目(No.20101224)

摘　　要：为了加强对桩承式路堤中土拱效应的理解,采用有限元方法对不同桩间距、填土高度和内摩擦角的情况进行了参数敏感性分析。计算结果表明,对于填土高度与桩净间距之比H/(s-a)≤1的低路堤,填土中的破坏面为通过桩边缘的竖直面;而对于H/(s-a)≥1.5的高路堤的情况,最终填土中将发展成类似经典地基承载力理论中的由弹性楔体、径向剪切区和被动破坏区组成的区域。基于有限元得到的破坏模式,建立了土拱效应的二维简化分析方法,并与有限元和文献收集得到的试验数据进行了比较。结果表明,由于采用了合适的破坏面假设,简化方法的计算结果可靠合理。To improve the understanding of the soil aching effect in the embankment fill, a parametrical study using finite element method is performed. In the analysis, the pile spacing, the fill height and the friction angle of embankment fill were varied. It is found that for low fill height relative to the net pile spacing, H/（s-a）≤l, the failure surface is vertical or slightly inclined which starts from the pile edge and goes through the whole fill height. For H/（s-a）≥ 1.5, the developed failure surface is similar to that assumed in the Terzaghi＇s bearing capacity theory; there are triangular elastic zone, radial shear zone and passive zone in the embankment fill. By using the failure surface shape determined from the FEM, a two-dimensional simplified method to evaluate the soil arching effect is proposed. The computed stress reduction ratios are compared with FEM results and the experimental data collected from literatures; it is found that the present simplified method can predict reliable results.

关 键 词：桩承式路堤 土拱效应 有限元 破坏模式 应力折减系数 

分 类 号：TU470[建筑科学—结构工程]