某高速公路隧道二衬开裂成因分析及处治研究

Evaluation and Mitigation of the Secondary Lining Cracking of an Expressway Tunnel

随着高速公路建设向山区纵深推进,受走廊带、地形地貌、环水保要求等多因素的制约,隧道作为结构物的占比越来越大。在多年的隧道建设和运营实践显示,衬砌裂缝是最为常见的主要病害之一。如何有效预防和处治衬砌裂缝是一个关乎隧道安全建设和运营的关键技术难题。以某高速公路隧道二衬和仰拱发生裂缝的实际情况为依托,通过采用隧道监控量测的方式,查明衬砌裂缝的分布特征,找出该隧道二衬开裂及变形规律。在此基础上,对裂缝的产生进行成因分析,提出了锁脚、隧底加固、增设泄水管、粘贴钢板二衬加固等处治措施,取得了良好的效果,也为类似工程的处治提供借鉴。

With the expressway construction going into the mountain areas,the number of tunnels as structures are increasing due to the restriction of the highway alignments,the landform,the environmental protection requirements,the water sources and other factors.From many years of tunnel construction and operation practice experience,lining cracks are one of the most common major hazards.Effectively prevent and mitigate the lining cracking are the key technical problem related to the safety of the tunnel construction and operation.Based on a case history of the secondary lining cracking at the top of an expressway tunnel,this paper evaluates the distribution characteristics of cracks in the lining system,the patterns of these cracks and the deformation in the secondary lining of the tunnel by means of tunnel monitoring and measurement.On this basis,factors that inducing cracks are analyzed,and mitigation measures such as reinforcing the bottom,adding drainage pipe,and installing steel plate in the secondary lining reinforcement are proposed,which have achieved satisfactory results and also provide a reference for the mitigations of similar projects.