动载作用下桩网结构低路基双层土工格栅力学特性  

Research on the Mechanical Characteristics of Double-deck Geogrids of Pile Net Structure of Low Embankment under Dynamic Load

作　　者：魏平[1] 魏静[1] 杨松林[1] 张栋[1] 马迎利 

机构地区：[1]北京交通大学,北京100044 [2]北京工业职业技术学院,北京100042

出　　处：《铁道工程学报》2017年第7期30-35,共6页Journal of Railway Engineering Society

基　　金：北京市教育委员会科技计划项目(KM201410853004);北京工业职业技术学院科研重点项目(bgzyky 201701z)

摘　　要：研究目的:为研究列车动载作用下的土工格栅-桩间土-桩相互作用机理,建立桩网结构低路基加筋垫层双层土工格栅动力分析有限元模型,分析列车动载作用下的土工格栅的受力及变形规律。研究结论:(1)路基结构加筋垫层中,沿线路纵向方向的双层土工格栅其下层格栅拉力较大,列车荷载作用下,下层土工格栅的拉力增量较大;(2)上层土工格栅的竖向位移较大;沿路基横断面方向,上层土工格栅拉力较大,路基中心到坡脚的上、下双层土工格栅拉力的差逐渐减小;(3)列车荷载下的下层土工格栅拉力增量较大;(4)双层土工格栅能够减小其竖向位移和动荷载后格栅拉力的增量,进而减小沿线路纵向和沿路基横断面方向上的不均匀沉降,且较单层土工格栅更易发挥格栅的张力膜效应;(5)本研究可为铁路路基结构土工格栅工作机理分析提供思路和方法。Research purposes： The dynamic analysis model software was built to investigate characters of double - deck geogrids within pile net structure in low embankment under train dynamic load. Both of the interaction mechanism among dynamic load, double - deck geogrids, pile and soil, and the force or deformation law of double - deck geogrids were studied. Research conclusions：Under train dynamic load, for the longitudinal section geogrid, pull stress of the substratum geogrid is higher than of the superstratum. For the transvers section geogrid, pull stress of the superstratum geogrid is higher than of the substratum and led to a very small difference value from subgrade center to slope toe. Tensioned membrane effect, the total pull stress and the reduction of single geogrids stress were all be better for the double - deck than for the single one. Double - deck geogrids can reduce the incremental value of geogrids pull stress and led to stucture stable. It will provide method of working mechanism for geogrids of railway roadbed structure in this research.

关 键 词：动荷载 桩网结构 低路基 土工格栅 

分 类 号：TU435[建筑科学—岩土工程] U416.1[建筑科学—土工工程]