高速公路隧道边墙开裂下沉机理分析及处治措施

Mechanism Analysis and Treatment Measures for Sinking and Cracking of Side-wall for Operational Expressway Tunnel

针对某运营高速公路隧道边墙下沉开裂的破坏情况,通过现场调研、专项检测和数值模拟手段分析了基岩遇水软化导致的病害发生机理,提出了注浆钢花管锁脚、衬砌结构加固、疏通排水、增设仰拱等综合处治措施及效果评价方法。研究表明:衬砌边墙纵向裂缝和结构下沉主要由基岩软化、承载力降低引起的水平作用力增加以及不均匀沉降导致;地下水敏感围岩的隧道衬砌结构设计应设置仰拱。本案例采用注浆钢花管锁脚、衬砌结构加固、疏通排水、增设仰拱等综合处治措施,有效控制并成功处治了隧道边墙下沉开裂病害,可为类似工程病害整治提供参考和借鉴。

Aiming at the damages of side wall sinking and cracking of an expressway tunnel,the possible causes are investigated by field investigation and special detection,and the influence of softening of bedrock by water on lining structure is analyzed by numerical simulation.Based on the analysis results,the locking foot and lining of grouting steel flower tube are put forward.Comprehensive treatment measures such as structure reinforcement,dredging and drainage,adding inverted arch and so on are taken,and the effect of treatment measures is analyzed and evaluated.The results show that the longitudinal cracks of the lining side wall are mainly caused by the increase of the horizontal force on the lining structure after the softening of the bedrock;the sinking of the side wall is mainly caused by the softening of the surrounding rock of the basement and the decrease of the bearing capacity,resulting in the uneven settlement of the structure;the inverted arch should be set up in the design of the lining structure in the surrounding rock sensitive to groundwater.In order to resist the unfavorable stress state caused by the softening of surrounding rock,the comprehensive treatment measures such as locking foot of grouting steel pipe,reinforcement of lining structure,dredging and drainage,and installation of inverted arch are put forward to achieve good treatment effect,so that the tunnel diseases can be effectively controlled and successfully treated,which can provide reference for the treatment of similar engineering defects.