浙江苍岭隧道左线凝灰岩突水现象工程地质特征研究

Study on Engineering Geological Characteristics of Water Bursting from Tuff of Zhejiang Cangling Tunnel

研究目的:对发生在浙江苍岭隧道施工中发生在凝灰岩中的突水事故的成因、特点和主要控制因素进行研究,以便更好地对其进行预测和防治。研究方法:根据发生突水事故的浙江苍岭隧道的现场地质观测资料,具体分析其形成的规模、位置、诱发因素以及地质条件,从地质工程的角度,对突水发生地段隧道的岩石组成、地质构造、现代构造应力场以及地下水等工程地质特征进行探讨,进而发现其规律和防治预测的特点。研究结果:苍岭隧道施工中发生的突水事故受到地质构造和地下水活动特点的强烈控制,虽然凝灰岩本身不溶于水,但在现代构造应力场的作用下形成的特殊的构造,为地下水的运移和赋存提供了通道和场所,是造成突水的主要原因。并在此基础上,借助TSP-203+地质超前预报预报系统,建立了苍岭隧道突水灾害的超前预报识别标志,提出了"先疏导排水、后注浆封闭"的突水防治措施。研究结论:对于隧道出现的土水灾害,首先要进行其工程地质的研究,在此基础上再进行准确的预测和合理的防治是有效防治隧道灾害的正确方法和步骤。

Research purposes： The studies are done on the causes, characteristics and main control factors of water bursting from tuff in construction Zhejiang Cangling Tunnel for the purposes of doing prediction and treatment of it. Research methods： Based on the site geological survey information about water bursting of Cangling Tunnel, the concrete analyses are made for the scale, location, causes and geological conditions of water bursting and the explorations are made on the characteristics of composite of surrounding rock, geological structure, modern structural stress field and underwater from the view of geological engineering point in order to seek the regularity of water bursting and better treatment. Research results：Water bursting in Cangling Tunnel is controlled by the geological conditions in the zone. Although tuff is not dissolved in water, but the special structure formed under the effect of modern stress field provides the passage and stored area for the underwater. This is the main cause for water bursting. Therefore, the geological prediction in advance system with TSP- 203 and relative marks for it should be established and relative measures should be taken with theprinciple of “Drainage first and grouting block second”. Research conclusions：For the soil and water disasters occurred in tunnel, first, the research should be done on the engineering geology, then the prediction and treatment should be carried out.