四连拱隧道拓宽为双洞双层隧道稳定性分析

Stability analysis of expanding a four arch tunnel into a double hole double layer tunnel

为研究既有隧道拓宽时稳定性,以国内某四连拱隧道拓宽为双洞双层隧道项目为依托,利用荷载结构法和地层结构法理论,采用有限元数值模拟方法,分析围岩稳定性及衬砌结构支护能力。结果表明:施工完成后围岩最大沉降位于西侧隧道拱顶上方,该值在允许10 cm的安全范围,从隧道结构位移及安全系数方面分析得出支护体系可有效保证隧道结构稳定。

In order to study the stability of existing tunnels during widening,based on a domestic project of widening a four arch tunnel into a double hole and double layer tunnel,using the theory of load structure method and stratum structure method,finite element numerical simulation method was used to analyze the stability of surrounding rock and the support capacity of the lining structure.The results show that the maximum settlement of surrounding rock after construction is located above the arch of the west tunnel,which is within the allowable safety range of 10 cm.From the analysis of tunnel structural displacement and safety coefficient,it is concluded that the support system can effectively ensure the stability of the tunnel structure.