涵洞-填土-地基共同作用的涵洞减载效应研究  

Study on the Load Reduction Effect of Culvert-Fill-Foundation Interaction

作　　者：陶庆东[1,2] 何兆益[1] 贾颖[1,3] TAO Qingdong;HE Zhaoyi;JIA Ying(School of Civil Engineering,Chongiqing Jiaotong Univ.,Chongqing 400074,China;Department of Architectural Engineering,Mianyang Polytechnic,Mianyang 621000,China;Guizhou Transportation Planning Survey&Design Institute Co.,Ltd.,Guiyang 550000,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]绵阳职业技术学院建筑工程系,四川绵阳621000 [3]贵州省交通勘察规划设计研究院股份有限公司,贵阳550000

出　　处：《三峡大学学报（自然科学版）》2020年第5期67-74,共8页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金(51278513);四川省教育厅项目(18ZB0307,16ZB0462);贵州省交通厅项目(201412102601)。

摘　　要：为缓解高填方盖板涵顶部竖向土压力集中的状况,进行了室内填土-涵洞-地基模型试验,通过监测涵洞顶部与底部竖向土压力,验证了FLAC数值模型的精度与可靠性,然后在该数值模型的基础上,对涵底地基压缩减载、涵底地基与涵顶联合压缩减载时各工况进行了数值模拟.结果表明:在涵底地基上设置固定尺寸的地基压缩区,可在不显著增加涵洞竖向沉降的情况下,有效减小涵顶竖向土压力;当仅在涵底地基上设置压缩减载区,压缩区深度为0.5 D(D为涵洞高度),宽度为2B(B为涵洞基础宽度)时,对缓解涵洞顶部土压力集中效果最好;当为涵顶与涵底联合压缩减载时,在保证最优的涵底地基压缩减载情况下,涵顶压缩区厚度为0.6 m时对应的涵顶竖向土压力减小最显著;当涵顶上方填土高度为28 m,且在最优的联合减载情况下,涵顶竖向土压力与涵底竖向压力的最大减载率分别为61.13%和45.42%.In order to alleviate the vertical earth pressure concentration of high fill cover plate culvert,based on the working mechanism of culvert-fill-foundation,a laboratory culvert model test is established.By monitoring the vertical earth pressure at the top and bottom of the culvert,the accuracy and reliability of the FLAC numerical model are compared and analyzed.On the basis of this model,the numerical results of foundation compression load reduction and foundation and culvert top combined compression load reduction are calculated.The results show that setting a fixed size foundation compression zone on the culvert bottom foundation can effectively reduce the vertical earth pressure on the top of the culvert without significantly increasing the vertical settlement of the culvert.When the compression load reduction zone is set only on the culvert foundation,the depth of the compression zone is 0.5 D(D is the culvert height)and the width is about 2 B(B is the culvert foundation width),the effect of relieving the concentration of earth pressure at the top of the culvert is the best.When the compression load reduction zone is set up at both the top and the bottom of the culvert,under the condition of ensuring the optimal foundation compression,the vertical earth pressure at the top of the culvert decreases most significantly when the thickness of the compression zone at the top of the culvert is 0.6 m.When the filling height above the culvert top is 28m,the maximum load reduction rates of the vertical earth pressure at the top of the culvert and the contact pressure at the bottom of the culvert are 61.13%and 45.42%,respectively.

关 键 词：高填方涵洞 减载机制 基底压力 竖向土压力 减载率 

分 类 号：U449.1[建筑科学—桥梁与隧道工程]