隧道台阶法施工中台阶长度的优化分析

Optimization Analysis of Step Length in Tunnel Construction by Bench Method

为对比隧道台阶法施工中台阶长度对隧道施工的影响,选取合理的台阶长度,提高台阶法施工时的安全性,以云南省某隧道为依托,运用数值模拟的方法对比不同台阶长度下初期支护的变形及受力特征,最后通过现场实测结果与模拟结果的对比分析得出:当上台阶长度取值为1倍~2倍洞跨时,能够使初期支护的变形和受力更加合理,保证了初期支护结构的安全性和施工便利性,对类似地质条件下采用台阶法施工的隧道具有一定的借鉴意义。

Reasonable step length can improve the safety of tunnel construction by bench method.In order to compare the influence of step length in tunnel construction,based on a tunnel project in Yunnan Province,the deformation and stress characteristics of primary support structure under different step lengths are compared by means of numerical simulation.After comparing and analyzing the results obtained from field measurement and the simulation,it is shown that:when the length of the upper step is1-2 times of the tunnel span,the deformation and stress of the primary support can be more reasonable,and the safety and construction convenience of the primary support structure can be guaranteed,which has certain reference significance for tunnel construction by bench method under similar geological conditions.