挤压带对偏压隧道边坡稳定性的影响与治理

以贵州某高速公路一浅埋偏压连拱隧道为背景,从工程实际出发,结合有限元数值模拟探讨挤压带对偏压隧道边坡稳定性的影响及治理措施。分析结果表明,挤压带对边坡稳定性起到主要控制作用。有限元数值模拟结果显示,由于挤压带的存在,边坡顶部沿挤压带下缘处开裂,这与实际观察结果一致;计算结果还表明,在右硐室、强风化带及挤压带交接处,出现剪应力集中,导致局部剪切破坏,边坡可能沿着此条潜在滑动面失稳。针对挤压带力学性能差以及由此引起强风化带开裂、剪切损伤而导致强度下降的情形,提出了抗滑桩与钢花管注浆共同作用的治理方案。地表注浆有利于提高隧道顶板岩体的完整性和强度,对隧洞施工安全及为重要。

Slope Stability and Treatment of Unsymmetrically Loaded Tunnel with Effect of Compressed Zone

Taking one shallow-embedded and double-arch tunnel in Guizhou Province as the engineering background,the slope stability and harness of unsymmetrically loaded tunnel with effect of compressed zone are discussed by geological investigation and finite element analysis.It proves that compressed zone is main source to control slope stability.The result of numerical analysis demonstrates that the top of slope is cracked because of compressed zone existing,and coincides with in-situ investigation.The shear stress concentration and local shear failure are observed at the joint of right tunnel,strong weathering and compressed zone by numerical analysis,and the slope may slide along the potential slide interface.In order to prevent slope from failure,the slope is rei-nforced by anti-slide pile and injecting grout through steel perforated pipe.Injecting grout can improve the int-egrity and strength of rock mass of tunnel roof.It is especially important to the safe construction of tunnel.