非对称小净距隧道合理施工方法和工序分析

Study on mechanical characteristics of unsymmetrical closely-spaced tunnels under different construction methods and processes

通过有限元软件ANSYS对非对称小净距隧道进行了二维弹塑性数值模拟,研究分析了采用不同施工方法及工序时对隧道的力学特性、围岩稳定性的影响,结果表明:从总体看,隧道分部开挖要优于全断面开挖,但分部开挖由于多次扰动围岩,反而对中墙不利;先行洞断面较大时,其本身的存在对后行洞的影响也较大;隧道净距的变化对非小净距隧道的围岩稳定性有重要影响。

This paper made two dimensional elastic-plastic numerical simulation to asymmetric small clear distance tunnel through finite element software ANSYS, researched and analyzed the influence to tunnel mechanical properties, surrounding rock stability using different construction methods and process, the results showed that, in general, the tunnel division excavation was superior to whole section excavation, but the partial excavation due to multiple disturbance surrounding rock, unfavorable to mid-wall, when the first hole had larger section, its existence had larger influence to after hole, the tunnel clear distance change had important influence to asymmetric small clear distance tunnel surrounding rock sta- bility.