胡麻岭隧道富水粉细砂地层水稳特性研究

Research on the Water Stability Characteristics of the Stratum of Humaling Tunnel Rich Water Silty-Fine Sand

兰渝铁路胡麻岭隧道大段落穿越第三系富水低渗透性粉细砂地层,该地层具有复杂敏感的水稳特性,施工难度极大。文中对该围岩基本物性参数、液塑限、单轴抗压强度与含水率的关系、抗剪强度等进行了试验研究,采用动力触探试验判定了该地层存在振动液化现象。同时结合胡麻岭隧道工程实例,对施工中不同水害现象进行归类研究,描述了该地层隧道开挖后在地下水渗流作用下围岩稳定性的变化特征,总结了不同水害现象的产生机理和条件。可为同类地下工程地质研究做参考。

The large paragraphs of Humaling tunnel of Lanzhou-Chongqing railway pass through the stratum of the Neogene system water rich low permeability silty-fine sand, the construction is very difficult. This paper tested and studied the basic physical parameters of the surrounding rock, liquid plastic limit, uniaxial compressive strength and water content, shear strength, and determined the formation vibration liquefaction phenomenon exists by using dynamic hammer test. Based on the construction of Humaling tunnel project, the different water disaster phenomenon were classified and researched,the change characteristics of surrounding rock stability of the strata after excavation in groundwater seepage were described, the mechanism and conditions of the different water disaster phenomenon were summarized. It can be a reference for the similar underground engineering geological research.