穿越软硬突变地层隧道纵向不均匀沉降分析  

Analysis of Longitudinal Non-Uniform Settlement of Tunnel Through Soft and Hard Mutation Strata

作　　者：兰庆男 彭鹏[1,2] 李长俊 张志强 林迪睿[1,2] Lan Qingnan;Peng Peng;Li Changjun;Zhang Zhiqiang;Lin Dirui(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,P.R.China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,P.R.China;Zhejiang Institute of Communications Co.,Ltd.,Hangzhou 310000,P.R.China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]西南交通大学土木工程学院,成都610031 [3]浙江数智交院科技股份有限公司,杭州310000

出　　处：《地下空间与工程学报》2022年第3期1044-1050,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家高铁联合基金项目(U1934213);国家自然科学基金(51878572)\。

摘　　要：纵向穿越软硬突变地层的盾构隧道在外部施工因素影响下极易产生不均匀沉降,从而诱发管片环间错台、螺栓剪断和接缝渗漏水等病害。为进一步研究外部因素对其竖向位移的影响,基于Winkler弹性地基梁理论推导任意荷载作用下隧道竖向位移公式,结合Boussinesq解采用两段分析法分析地面堆载大小、尺寸以及隧道埋深对盾构隧道竖向位移规律的影响。以厦门地铁2号线某区间为工程实例,验证理论公式的合理性。研究结果表明:在地面堆载作用下,隧道竖向位移曲线多数服从正态曲线分布,且软土区盾构隧道竖向位移普遍大于硬土区;堆载长度对最大竖向位移的影响有限,当堆载长度超过一定界限时,最大竖向位移不再增大,但其范围会随之扩大;当堆载宽度超过一定限度时,竖向位移曲线基本不再发生变化;当埋深较浅时,软硬土交界处盾构隧道两侧竖向位移差异不大,随着埋深的增大,隧道最大竖向位移逐渐向软土区偏移。研究结果可为纵向穿越软硬突变土层地铁盾构隧道的设计提供参考依据。Under the influence of external construction factors, uneven settlement is easy to occur in shield tunnel in longitudinal soft and hard mutation stratum, which leads to such diseases as cross-platform between segment and ring, bolt shearing and joint leakage. For further study of the external factors on the shield tunnel longitudinal soft mutation formation in the influence of the vertical displacement, tunnel vertical displacement formula was derived under arbitrary load based on Winkler elastic foundation beam theory, and stack size on the ground, and the size of the stack, and vertical displacement of the tunnel buried depth of shield tunnel analysis combined with Boussinesq solution. A section of Xiamen Metro Line 2 is taken as an engineering example to verify the rationality of the theoretical formula. The results show that the vertical displacement curves of most shield tunnels follow the normal curve distribution under ground overloading, and the vertical displacement of shield tunnels in soft soil area is generally greater than that in hard soil area. The effect of the loading length on the maximum vertical displacement is limited. When the loading length exceeds a certain limit, the maximum vertical displacement does not increase, but the range of vertical displacement will expand accordingly. When the load width exceeds a certain limit, the vertical displacement curve does not change. When the buried depth is relatively shallow, the vertical displacements on both sides of the shield tunnel at the interface of soft and hard soil have little difference, but there is uplift phenomenon in the soft soil area. With the increase of the buried depth, the maximum vertical displacement of the tunnel gradually shifts to the soft soil area. The research results can provide a reference for the design of metro shield tunnel longitudinal through soft and hard mutation soil layer.

关 键 词：盾构隧道 纵向不均匀沉降 软硬突变土层 弹性地基梁 地面堆载 

分 类 号：TU91[建筑科学—建筑理论]