摘要
为精确地计算涵洞顶部竖向土压力集中系数,进行了土石混合体填料—涵洞室内模型试验。利用试验结果标定了FLAC数值模型,运用该数值模型研究了结构参数与填料性质对涵洞力学特性的影响。结果表明:在侧墙顶部以下0.35D(D为侧墙高度)处出现最大水平负弯矩,在0.67D处出现水平弯矩反弯点;含石量对侧墙上水平土压力影响显著,含石量为50%和70%时,侧墙上产生的侧向水平土压力更大;随着涵洞顶板厚度的增加,涵顶边缘竖向土压力随之增加,涵顶中心竖向土压力随之减小;随着泊松比的增加,侧墙上正负弯矩的反弯点位置逐渐下移,反弯点的位置变化区间为[0.49D,0.71D];数值模拟结果得到的涵顶边缘竖向土压力集中系数大于相关规范与研究成果的上限值,涵洞结构边缘所受竖向土压力大于理论计算得到的竖向土压力。
In order to calculate the vertical earth pressure concentration factor above the culvert accurately,carrying out the indoor model test of soil-rock mixture( SRM) filling-culvert. The FLAC numerical model was calibrated by the indoor model test results. Meanwhile,the effects of structural parameters and filling properties on the mechanical properties of culverts were studied by using the approved FLAC numerical model. The results showed that:the maximum horizontal negative bending moment occurs at 0.35 D( D is the height of the side wall) below the top of the side wall,and the reverse bending point of the horizontal bending moment occurs at 0.67 D. The influence of rock block proportion of fillings on the horizontal earth pressure on the side wall is significant. When the stone content is50% and 70%,the horizontal earth pressure on the side wall is greater. With the increase of the thickness of culvert top slab thickness,the vertical earth pressure at the edge of the culvert top slab increases,and the vertical earth pressure at the center of the culvert top slab decreases. With the increase of Poisson of soil-rock mixture,the position of the reverse bending point of the positive and negative bending moment on the side wall moves down gradually,and the change range is [0. 49 D,0. 71 D]. Compared with the current relevant specifications and research results,the simulation results show that the earth pressure concentration factor at the culvert top edge is larger than the upper limit values of the codes and research results. The edge of slab culvert structures are subject to greater vertical earth pressure than theoretical ones.
作者
陶庆东
何兆益
贾颖
Tao Qingdong;He Zhaoyi;Jia Ying(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,P.R.China;Department of Architectural Engineering,Mianyang Polytechnic,Mianyang,Sichuan 621000,P.R.China;Guizhou Transportation Planning Survey&Design Academe Co.,Ltd.,Guiyang 550000,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2021年第2期468-478,共11页
Chinese Journal of Underground Space and Engineering
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)。
关键词
土拱效应
盖板涵洞
土石混合体
模型试验
竖向土压力
soil arch effect
slab culvert
soil-rock mixture(SRM)
model test
vertical earth pressure