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地铁隧道由于线形的需要一般间距较小,在浅埋的条件下,如果两洞纵向施工距离控制不当,后行洞的施工很容易对先行洞已经产生的应力重分布围岩造成不良的二次扰动,极易导致围岩大变形、失稳等问题。本文以武汉地铁浅埋段矿山法施工区间为对象,采用有限元软件PLAXIS对四种不同施工纵向间距条件下,先行洞及后行洞的位移分布、塑性区状态等进行了分析计算,并与实测位移进行了对比。结果表明,纵向间距越大,围岩的相互扰动效应越小,针对武汉地铁工况,得出了合理掌子面距离为1.5倍隧道洞径的结论。论文的研究方法和结论对类似工程可提供较好的参考和借鉴。
Subway tunnel due to the need for the general line spacing smaller, under shallow conditions, if the vertical distance between the two holes is not properly controlled, the construction of the back hole is very easy for the first hole has been produced stress redistribution surrounding rock caused by the poor second Disturbance, can easily lead to large deformation of the surrounding rock, instability and other issues. In this paper, the mining section of Shallow Buried Section in Wuhan Metro is taken as an object. The displacement distribution and the plastic zone state of the first and the succeeding tunnel under four different longitudinal construction conditions are analyzed by finite element software PLAXIS. The measured displacement is compared. The results show that the larger the longitudinal spacing, the smaller the mutual disturbance effect of surrounding rock. According to the Wuhan subway condition, the conclusion is drawn that the distance of the proper face of the tunnel is 1.5 times the tunnel diameter. The research methods and conclusions of the dissertation can provide a good reference and reference for similar projects.