高填减载明洞土拱形态及衬砌结构力学性能研究  

Study on the influence factors of soil arch morphology and mechanical properties of lining structure in high-filled cut-and-cover tunnels

作　　者：姚泽文 李盛[1] 马莉[1] 尤著刚 余云燕[1] 班学锋 YAO Zewen;LI Sheng;MA Li;YOU Zhugang;YU Yunyan;BAN Xuefeng(Civil Engineering College,Lanzhou Jiaotong University,730070 Lanzhou,China;China Railway Investment and Construction Group Co.,Ltd.,102600 Beijing,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]中建铁路投资建设集团有限公司,北京102600

出　　处：《应用力学学报》2025年第2期339-346,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.51668036,51868041);甘肃省基础研究创新群体项目(No.21JR7RA347)。

摘　　要：高填减载明洞的减载机理是通过增大回填土内部的沉降差使土体中产生土拱效应从而降低明洞上方土压力,以此减小衬砌结构的受力。高填减载明洞的减载效果取决于土拱效应的强弱,然而,土拱效应强弱与土拱形态有何关系尚不明确,为了优化明洞设计,提高衬砌结构安全性,需明确土拱形态对土拱效应的影响。因此,基于有限差分软件FLAC3D,以槽宽比和边坡角度为变量,研究应用EPS(expanded polystyrene)板+混凝土柱减载的高填方明洞回填土土压力、回填土的土拱形态以及衬砌结构受力,从土拱形态角度分析槽宽比和边坡角度对高填减载明洞土压力、衬砌结构受力的影响。结果表明:①明洞拱顶和仰拱外侧受压,明洞外侧受拉受压交界点出现在拱腰处,衬砌结构边墙与拱腰连接处弯矩最大;②减小槽宽比或增大边坡角度,会使土拱效应越显著,减载效果越好,衬砌结构所受轴力越小,衬砌结构更安全;③土拱效应强弱是由土拱厚度和明洞上方土拱区域面积决定的,土拱厚度越大、明洞上方土拱区域面积越大,减载效果越好,与土拱位置和土拱区域总面积无关。实际工程中,应通过控制土拱的厚度和明洞上方土拱区域的面积来优化结构受力。The load reduction mechanism of high-filled cut-and-cover tunnels is reducing the earth pressure above the tunnel by increasing the settlement difference inside the backfill soil,so as to reduce the stress of the lining structure.The load reduction effect of high-filled cut-and-cover tunnels depends on the strength of soil arch effect.However,the relationship between the strength of soil arch effect and soil arch morphology is not clear.In order to optimize the design of lining structure and improve the safety of lining structure,it is necessary to clarify the influences of soil arch morphology on soil arch effect.Therefore,based on the finite difference software FLAC3D,with the groove and tunnels width ratio and slope angle as variables,the earth pressure of backfill,the soil arch morphology of backfill and the stress of lining structure of high-filled open-cut tunnel with EPS plate and concrete column load reduction are studied.The influences of groove and tunnels width ratio and slope angle on the earth pressure of high-filled open-cut tunnel and the stress of lining structure are analyzed from the perspective of soil arch morphology.The results show that the vault and inverted arch of the tunnel are subjected to compression,and the lateral side of the side wall is subjected to tension,and the boundary point of tension and compression outside the tunnel appears at the arch waist.Reducing the groove and tunnel width ratio or increasing the slope angle will make the soil arch effect more obvious,the load reduction effect is better,the stress of the lining structure is smaller,and the lining structure is safer.The strength of soil arching effect is determined by the thickness of soil arch and the area of soil arch area above the open.The larger the thickness of soil arch is,the larger the area of soil arch area above the open tunnel is,and the better the load reduction effect is,which is independent of the position of soil arch and the total area of soil arch area.In practical engineering,the structural stress sh

关 键 词：高填减载明洞 槽宽比 边坡角度 土拱形态 土拱厚度 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]