【作者】 陈强；

【导师】 胡厚田；

【作者基本信息】 西南交通大学 ， 岩土工程， 2005， 博士

【摘要】 岩溶储气长隧道工程建设中地下水、天然气及其它不良工程地质条件对隧道施工安全、工程质量、结构稳定具有重要的控制作用,往往是岩溶山区长隧道工程建设的控制性因素。本文结合渝(重庆)—怀(化)铁路线圆梁山隧道工程地质研究,从岩溶作用、石油天然气问题、环境影响三个方面对岩溶储气长隧道工程地质进行了系统研究,初步建立了一套研究体系和基本理论框架。主要取得了以下成果: 一是岩溶地质研究。 (1) 碳酸盐岩区的化学热力学研究。分析了岩溶地下水的碳酸与二氧化碳分压对岩溶作用产生与发展的影响;应用多组分综合分析方法,采用地下水全分析结果设计了五个化学反应方程式,通过活度、反应平衡常数及吉布斯自由能之间关系的热力学关系及二氧化碳气体分压,构建了评价地下水侵蚀性的两个化学反应判据,准确地分析出地下水的侵蚀性,为工程实践提供了一种新的地下水侵蚀性分析、评价方法;并分析了地下水对混凝土的碳酸型、硫酸盐型与硫氢酸型侵蚀以及混凝土中碱—骨料反应。 (2) 碳酸盐岩区的岩溶动力学研究。根据矿物溶解与沉淀的关系,将岩溶储气长隧道分成深埋与开挖两个区域,依据确定的化学模型,利用水质的相对和绝对含量,运用化学热力学、化学动力学理论和相关分析方法进行溶蚀量或溶蚀模数的计算,得出隧道深埋区溶蚀总模数比隧道开挖区大10多倍的结论;采用化学热力学和化学动力学与地下水动力学理论相结合方法,给出了碳酸盐岩区水动力学和化学动力学模型,以及相关参数的计算公式。 (3) 岩溶突水突泥研究。讨论完善了岩溶突水突泥的定义,分析了岩溶突水突泥的基本特征与分类;应用断裂力学原理研究了岩溶突水突泥中的水力劈裂作用,得出深埋岩体为Ⅱ型裂纹扩展,给出了Ⅱ型裂纹扩展的临界水头值的计算公式和裂隙张开度在压裂作用下的计算公式:通过突水突泥破坏性分析,计算了圆梁山隧道“9.10”特大突泥事故冲击力,并应用离散单元法对突水突泥的突出过程进行数值模拟,动态地再现了圆梁山隧道突水突泥运动过程。 二是石油天然气地质研究。岩溶储气长隧道施工中发生的天然气突出不仅包括揭煤过程中的瓦斯突出,更主要的危害是石油天然气等非伴煤型天然气突更多还原

【Abstract】 Groundwater, natural gas and other bad geological condition are dominative factors for tunnel construction security, project quality and structure stability of in the long tunnel engineering construction with gas and karst. Based on studying engineering geology of the Yuanliangshan tunnel in the paper, the research systems and basic theories of karst and gas tunnel are established from the karst, gas and engineering environment. The main research contents in the paper are:First, karst geology research. (1) Chemical thermodynamics research in the district of carbonate rocks. The influence of produce and develop of karst function is analyzed by the partial pressure function of carbonic acid and carbon dioxide of groundwater. Based on many comprehensive analytical methods to composition of the groundwater, five chemical reaction equations are designed and carbon dioxide gas partial pressure and the direction of chemical reaction are set up. With the erosion accurately of groundwater, a new theory and a method comparatively of groundwater corroding are offered in the project practice. The corrosion of groundwater shows that the carbonic acid and sulphate and sulphur hydrogen and the reacts of alkalescence aggregate are playing corrosive rule to the concrete.(2) Karst dynamics research in the district of carbonate rocks. According to relation of mineral dissolution and deposition, there are deep bury district and excavated district about a gas storage long tunnel in karst. In the deep burry district of tunnel, with according to the definite chemical model and relative and absolute content of water quality, corrosive amount and corrosive modulus are carried on by the calculation of chemical thermodynamics and chemical dynamics theory and the correlation analytical method, It concluded that tunnel corrosion total modulus in the deep bury district is more than 10 times that of excavated district. Combined methods with chemical thermodynamics, chemical dynamics and the method of groundwater dynamics theory, water dynamics model, chemical dynamics model and some relevant calculation formula are provided in the district of carbonate rocks.(3) Research on karst water outburst and mud outburst. In the paper, the definition, primary condition, essential feature and classification, destructiveness of karst water outburst and mud outburst are discussed. Based on fracture mechanics principle, the hydraulic fracturing was studied in the course of water outburst and mud outburst. The formula of critical water pressure of type II crack and the equation of joint spacing variation are presented. Through destructive analyses ofkarst water outburst and mud outburst, the shock power of the mud outburst, are proposed in the Yuanliangshan tunnel "9.10 "accident. Karst water outburst and mud outburst are simulated by discrete element method; the moving process of water outburst and mud outburst is presented dynamical in the Yuanliangshan tunnel.Secondly, research on natural gas geology. In the paper, the mechanism of gas outburst, gas-solid coupled simulation by discrete element method and natural gas problems in the Yuanliangshan tunnel are studied. Petroleum gas and coal gas are produces in the karst region generally; the author thinks that gas outburst includes coal gas outburst and the petroleum gas outburst in the tunnel construction. Gas migration mechanism and mathematics model, including macroscopic and microcosmic mechanism, migration mathematics model, diffusion models, gas-solid coupled discrete element method numerical simulation of gas migration and mechanism of gas outburst are proposed. Based on the methods above-mentioned and monitoring data, some import problems are studied, such as natural gas storaging character in the entry of Yuanliangshan tunnel, forecast methods of natural gas, relation of natural gas and underground water, kinds of poisonous and harmful gas and its appraising, evaluation indexes of air quality in tunnel, etc.Based on the content above-mentioned, engineering application is studied. Systemic forecast methods of engineering geology are summarized, including TSP engineering geology forecast, geological radar, infrared acquisitions meter, forecast planning survey hole, geology description, engineering geology integrated analyzed, manage method systems, etc. Based on the mentioned methods, forecast of engineering geology are carried on in Yuanliangshan tunnel. Air quality in Yuanliangshan tunnel is analyzed by means of gas monitoring data.The third, research on environmental problems. The long tunnel karst environment and engineering environment are defined initially, the basic characteristics of karst environment and engineering environment are studied preliminary, and karst environment and engineering environmental system are analyzed in the long tunnel. At the same time, effect of tunnel engineering to environment in karst region is studied, the basic condition of karst leakage is analyzed, the classification of karst collapses in the long tunnel is set up, and forming condition and characteristic of karst collapses in the long tunnel are analyzed.Possible effects to environment of underground engineering construction of karst regions usually can presents the activating of ancient karst, increasing of modern karst development, changing of the hydrogeological environment, karst更多还原