基于桩网路堤简化分析方法的参数研究  

Parameters Analysis Based on Simplified Method to Solve Piled Embankment with Geogrid-Reinforcement

作　　者：刘飞成[1] 张建经[1] 闫世杰 曹礼聪 吴祚菊 LIU Feicheng;ZHANG Jianjing;YAN Shijie;CAO Licong;WU Zuoju(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering and Architecture,Southwest Universtiy of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南科技大学土木工程与建筑学院,四川绵阳621010

出　　处：《西南交通大学学报》2018年第6期1227-1236,共10页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金青年基金资助项目(51808466);四川省科技计划资助项目(2015SZ0068);中国铁路总公司科技研究开发计划课题(2015G006-D);交通运输部建设科技项目(2013318800020)

摘　　要：为研究桩网路堤各影响参数对其传力机制与变形特性的影响,通过理论推导得出了桩网路堤简化分析方法,采用该方法对桩网路堤进行参数分析.首先,综合考虑路堤填土土拱效应、地基支承作用和土工格栅效应,采用抛物线方程描述土工格栅变形,推导得到了针对正方形布桩型式的桩网路堤的分析方法;其次,通过与现场试验和目前主流设计方法对比分析,验证了本文计算方法结果可靠、计算过程简便;最后,采用该理论方法针对路堤高度、土工格栅刚度、地基软土厚度、软土模量对格栅张力、地基最大沉降和应力集中比的影响规律进行系统分析,在此基础上,引入非重复性二次方差分析对各参数的影响程度进行了量化对比.研究结果表明:格栅张力与路堤填高、格栅刚度、地基软土厚度成正相关关系,与软土模量成负相关关系;地基沉降与路堤高度、软土厚度成正相关关系,与格栅刚度、地基软土模量成负相关关系;应力集中比与路堤高度、格栅刚度、地基软土厚度成正相关关系,与地基软土模量成负相关关系;降低地基软土厚度和增大软土模量是保证土工格栅正常工作情况下尽可能增大应力集中比的有效手段;缩小桩间距或采用大桩帽,其优化效果好于提高格栅抗拉刚度.In order to analyze the influence of parameters on load transfer and deformation mechanisms of piled embankment with geogrid-reinforcement, a simplified method was proposed and employed for parameters analysis. A method including soil arching effect in granular material, subsoil resistance and membrane effect, is deduced and the deformation of the geogrid is expressed by Quadratic parabolic equation. Through comparative analysis with test data and other current design methods, it is found that the proposed method is conceptually and mathematically simple, and the results are reliable. The influence of embankment height, tensile stiffness of the geogrid, soft soil depth and compression modulus of soft soil on the tension of the geogrid, the settlement of soft ground and stress concentration ratio are studied using this method. The influence significance of these factors has been investigated by the evaluation theory of binary variance analysis of non-repeatability tests. The results show that the tension of geogrid is in proportion to embankment height, tensile stiffness of geogrid, soft soil depth, but in inversely proportion to compression modulus of soft soil. The settlement of soft ground is in proportion to embankment height, soft soil depth, but in inversely proportion to tensile stiffness, compression modulus of soft soil. Rsc is in proportion to embankment height, tensile stiffness, soft soil depth, but in inverselyproportion to compression modulus of soft soil. Decreasing soft soil depth and improving compression modulus of soft soil are both the effective methods to transfer more load to piles. Larger pile caps and small pile spacing should be prior to adopting the geogrid with high tensile stiffness in promoting transferring more load to piles.

关 键 词：桩网路堤 简化分析方法 参数研究 格栅张力 应力集中比 非重复性二次方差分析 

分 类 号：TU411[建筑科学—岩土工程]