采空区大跨连拱隧道围岩稳定分析及其加固

为了深入研究复杂地质条件下大跨度双连拱隧道围岩稳定性及施工关键技术,以沪昆高速公路灯草塘隧道为依托工程,基于有限差分软件,建立灯草塘隧道实际地质模型,重点进行双向六车道连拱隧道邻近采煤空洞时的围岩稳定数值计算,结果表明:靠近空洞一侧的主洞水平位移及拱顶沉降均大于另一侧的,隧道底板隆起位移也存在同样的规律;空洞与隧道之间围岩最大主应力大部分为拉应力,靠近空洞侧隧洞围岩最大主应力与另一侧相比较差异明显,且空洞与隧道之间塑性区范围较大。另外,基于数值分析结果,结合隧道实际空洞情况,研究了Ⅵ级围岩条件下隧道附近采煤空洞的处置及围岩的加固技术。

Stability analysis of surrounding rock of large-span arch tunnel in coal gob and its reinforcement

In order to study the surrounding rock stability and key techniques in the construction of large-span arch tunnel with complicated geology,Dengcaotang tunnel in the Shanghai-Kunming highway was investigated.Using the general finite difference software and establishing an actual geological model of Dengcaotang tunnel,the surrounding rock stability of six-lane arch tunnel with cavities was analyzed in detail.The results show that horizontal displacement and vault settlement of the side of the tunnel closed to the cavity are generally larger than those of the other side of the tunnel and the same holds for the uplift deformation;most of the maximum principal stress of the surrounding rock between tunnel and cavity is tensile stress.The maximum principle stress of the side of the tunnel closed to the cavity is different from that of the other side,and the plastic zone between tunnel and cavity is large.In addition,based on the numerical simulation results and the cavity state in the tunnel region,cavity treatments and surrounding rock reinforcement in coal gob were analyzed.