水压充填型溶腔对隧道稳定性影响的研究

发布时间：2018-04-06 01:01

本文选题：溶腔分布　切入点：水压充填型溶腔　出处：《重庆大学》2014年硕士论文

【摘要】：应用新奥法修建隧道，特别是富水区域的隧道工程时，承压地下水的防治若处理不当，将会造成突水，突泥等安全事故，严重影响隧道施工人员的生命安全及生产成本，同样也会对隧道运营期间的安全与维护产生影响。近年来，我国修建了大批山岭隧道、水下隧道、矿山隧道。这些隧道穿越富水地带的情况越来越多，其中以水压充填型溶腔对隧道的影响尤其明显，由于溶腔中存在高水压力，隧道建设过程极有可能诱发突水事故，严重威胁隧道施工安全。针对这一现状，在总结国内外现有研究成果的基础上，采用理论分析和数值模拟的方法对水压填充型溶腔与隧道掌子面间的安全厚度等问题进行了较为系统深入的研究。主要内容和成果如下： ①分析总结了有水压充填型溶腔的隧道发生突水灾害的影响因素，得出隧道突水主要受水压力、地应力、围岩结构和物理力学性质以及隧道所在区域工程地质条件因素的影响，同时也受到隧道断面大小、隧道开挖速度以及预留的安全厚度等施工因素的影响。 ②通过对依托工程进行数值模拟计算，分析了当溶腔中的水压力一定时，在流固耦合作用下，隧道发生突水事故时溶腔与隧道掌子面间的厚度，并提出了溶腔与隧道掌子面预留安全厚度的建议值，建议2MPa水压力作用下，预留安全厚度不宜小于6m. ③通过对依托工程进行数值模拟计算，分析了不同水压力作用下溶腔与隧道掌子面间的安全厚度值，地应力与水压力耦合作用下的安全厚度值，隧道不同围岩强度等级的安全厚度值，研究结果表明：水压力每增加0.5MPa，溶腔与隧道掌子面间的安全厚度宜增加2～4m；随着水平地应力数值的增大，安全厚度的取值也随之增加；随着围岩等级的降低，安全厚度取值也相应增大。 ④通过对依托工程数值模拟分析，研究不同溶腔分布下隧道与溶腔间的安全厚度，，研究表明，在III级围岩条件下，溶腔位于隧道顶部且溶腔内水压分别为1MPa、1.5MPa、2MPa时的安全厚度取值宜为8m、12m、16m；溶腔位于隧道右侧且溶腔内水压分别为1MPa、2MPa、3MPa时的安全厚度取值宜为6m、8m、10m。
[Abstract]:In the construction of tunnels with New Austrian method, especially in water-rich areas, if the prevention and treatment of confined groundwater is not proper, it will cause water inrush, mud outburst and other safety accidents, which will seriously affect the life safety and production cost of tunnel construction personnel.It will also have an impact on the safety and maintenance of the tunnel during operation.In recent years, China has built a large number of mountain tunnels, underwater tunnels, mine tunnels.There are more and more cases of these tunnels crossing the water-rich zone, especially the influence of water-filled cavity on the tunnel. Due to the existence of high water pressure in the cavity, the tunnel construction process is likely to induce water inrush accidents.The safety of tunnel construction is seriously threatened.In view of this situation, on the basis of summarizing the existing research results at home and abroad, the safe thickness between water pressure filled cavity and tunnel face is studied systematically and deeply by the method of theoretical analysis and numerical simulation.The main elements and outcomes are as follows:The main results are as follows: (1) the influencing factors of water inrush disaster in the tunnel with water pressure filling cavity are analyzed and summarized. It is concluded that the water inrush is mainly affected by water pressure, ground stress, surrounding rock structure and physical and mechanical properties, as well as the engineering geological conditions in the region where the tunnel is located.At the same time, it is also affected by the tunnel section size, tunnel excavation speed and reserved safety thickness and other construction factors.2 through the numerical simulation calculation of the supporting engineering, the thickness between the solution cavity and the tunnel face is analyzed when the water pressure in the cavern is constant, and under the action of fluid-solid coupling, when the water inrush accident occurs in the tunnel, the thickness between the solution cavity and the face of the tunnel is analyzed.It is suggested that the reserved safe thickness of the cavity and tunnel face should not be less than 6 m under the action of 2MPa water pressure.(3) through numerical simulation of the supporting engineering, the safe thickness between the cavity and the tunnel face under different water pressure and the safety thickness value under the coupling of in-situ stress and water pressure are analyzed.The results show that the safe thickness between the cavity and the tunnel face should be increased by 2 ~ 4 m for the increase of water pressure at 0.5 MPA, and the safe thickness increases with the increase of horizontal stress.With the decrease of surrounding rock grade, the safe thickness value increases accordingly.(4) through numerical simulation analysis of supporting engineering, the safe thickness between tunnel and cavern under different distribution of dissolved cavities is studied. The results show that, under the condition of III grade surrounding rock,The safe thickness of the solution chamber located at the top of the tunnel and the water pressure in the cavity is 1 MPa1. 5 MPA, respectively, the safe thickness of the solution cavity should be 8 mg / 12mt ~ (16) m, and the safe thickness value is 6 m ~ (8) m ~ (10) m when the water pressure in the cavity is 1 MPA ~ 2 MPA and the water pressure in the cavity is 1 MPA ~ (2) MPA ~ (2) ~ (-1) MPA, respectively, at the right side of the tunnel.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U457.2

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