峨汉高速庙子坪隧道岩溶发育特征及工程效应分析

以峨汉(峨眉山市—雅安市汉源县)高速庙子坪隧道为研究对象，首先通过对隧址区地质调查、示踪试验及统计现场揭露的溶洞数量，厘清隧址区岩溶发育特征并分析其控制因素，再通过整理分析现场监测数据探究岩溶发育对工程的影响。结果表明:隧址区岩溶在多溶控因素的耦合作用下表现出显著的不均性、集中性、方向性、连通性的特征。其中岩层岩性、地形地貌、水文地质、地质构造主要使得岩溶发育具有不均性和集中性；水文地质与地形地貌主要控制着岩溶发育方向和岩溶是否连通；气候则更进一步促进岩溶发育。隧址区岩溶发育的工程影响主要表现为隧道稳定性影响和隧道涌水，其中岩溶规模及尺寸对隧道稳定性有一定影响，但影响范围相对有限；而涌水使得隧道长期积水，在雨季时甚至使得人员、机械等被淹或冲毁，对隧道安全、进度、经济等造成严重影响。研究结论可为峨汉高速沿线隧道及其他类似工程的设计、施工、岩溶灾害防治等提供参考。

Analysis of karst development characteristics and influence of Miaoziping tunnel in E-Han expressway

Taking Miaoziping tunnel of E-Han expressway as the research object, firstly, through the geological survey, tracer test and statistics of the number of karst caves exposed on the site, the characteristics of karst development in the tunnel site are clarified and its control factors are analyzed, and then the engineering influence of karst development is explored based on sorting and analyzing the on-site monitoring data. The results show that: under the coupling action of multiple solution control factors, the karst in the tunnel site shows remarkable characteristics of heterogeneity, concentration, directivity and connectivity.Among them, rock strata lithology, topography, hydrogeology and geological structure mainly make karst development uneven and concentrated;hydrogeology and topography mainly control the direction of karst development and whether karst is connected;climate further promotes karst development. The engineering impact of karst development in the tunnel site area is mainly manifested as the impact of tunnel stability and tunnel water inflow. The scale and size of karst have a certain impact on the stability of the tunnel, but the scope of impact is relatively limited. However, the water inflow makes the tunnel accumulate water for a long time, which even makes the personnel and machinery flooded or destroyed in the rainy season, which has a serious impact on the safety, progress and economy of the tunnel. The conclusion can provide reference for the design,construction, karst disaster prevention and control of tunnel along the E-Han Expressway and other similar projects.