关角特长铁路隧道不良地质致灾机理及控制技术研究

发布时间：2018-04-26 04:31

本文选题：特长铁路隧道 + 突涌水　；参考：《北京交通大学》2014年博士论文

【摘要】：随着经济发展的需要,公路和铁路选线以长大隧道方式通过越岭地段越来越多,修建长大隧道往往要穿越复杂的地质条件。关角隧道是新建青藏铁路西格二线的重点、难点工程,长32.605km(进口高程为3378.72m,出口高程为3324.10m),是目前世界最长的高原铁路隧道。关角隧道区内地下水发育,岩体节理、裂隙发育,穿越断层破碎带长度达2782m(单线),中等富水区17.760km,突水压力最高达2.6MPa,最大涌水量达9000～9500m3/h,施工中工作面坍塌、支护结构变形开裂、大规模突涌水现象等工程问题频发,施工非常困难和危险。本文深入研究关角隧道不良地质致灾机理及控制技术,得到以下研究成果： (1)从资料调研和工程实践入手,以定性分析方法研究关角隧道的突涌水机理。采用流量测试、联通试验等手段,明确突涌水的水源补给。基于典型突涌水实例的地质资料、超前预报资料及设计施工情况,总结出关角隧道的水文地质模型。依据关角隧道地区岩溶发育特点和长距离反坡斜井的涌水、排水特点,提出了掌子面和洞身突涌水模式,并针对突涌水模式的机理,结合理论分析和数值计算方法,提出相应的处治对策,最终形成了一套适用于西北岩溶地区特长隧道的突涌水综合防治技术。 (2)采用经验总结和现场试验方法,指出裂隙-溶隙水作用在二次衬砌上的水压力分布规律具有局部高压且长期增大的特点。采用ANSYS建立荷载-结构模型,研究局部水压力作用下铁路单线隧道标准设计图的直墙和曲墙形式衬砌的受力特征和安全性,并对衬砌安全系数提高措施的作用效果进行分析,提出了局部高水压作用下衬砌的设计参数,填补了目前在局部水压显现明显地层中衬砌设计依据的不足。 (3)通过调研和经验总结,定性分析地下水对岩体力学性质的影响程度,对目前常用的规范中关于地下水对围岩等级的修正规定进行了归纳总结,发现了规范中存在的不足并提出改进建议。采用理论分析的方法,推导得到了考虑渗流力时隧洞的弹塑性解。通过数值模拟,基于流固耦合理论,采用ABAQUS得到了地下水位、埋深、初期支护刚度和支护时机不同时围岩-支护结构的应力分布和变形规律,为围岩-支护结构的力学响应分析提供了依据。 (4)采用现场试验,得到了富水破碎地层隧道的支护受力特征。基于松动圈理论,得到锚杆的设计长度。基于厚壁圆筒理论,得到喷射混凝土、格栅钢架、型钢钢架和组合支护体系的支护特征曲线。结合支护受力特征,提出了富水破碎围岩隧道的支护对策。 (5)针对断层破碎带出现的失稳现象,采用现场试验手段,得到支护、围岩的力学特性。根据试验数据结合理论分析,对支护方案提出了改进措施。经过采用FLAC3D建立数值模型进行论证,表明改进方案可有效的限制围岩变形,降低围岩的损伤程度和地质灾害发生的可能性。基于保证安全、节省成本、缩短工期的原则,对改进方案中的径向注浆方法进一步优化,提出了纵向分区径向注浆技术。通过数值模拟手段,采用FLAC3D建立三维弹塑性模型,对纵向分区的三个主要设计参数：注浆滞后掌子面距离、注浆段落长度、注浆段落间距进行计算,得到了满足不同变形控制效果的设计参数组合。
[Abstract]:With the need of economic development, highway and railway line selection is more and more through the way of long tunnel through the mountain area. The construction of long tunnel often passes through complex geological conditions. The Guan Jiao tunnel is the key of the Xizi second line of the new Qinghai-Tibet railway, the difficult project, the long 32.605km (the import elevation is 3378.72m, the export elevation of 3324.10m), is the present world The longest plateau railway tunnel in the border area is developed in the area of Guan Jiao tunnel, rock jointing and fracture development, the length of crossing fault fracture zone is 2782m (single line), 17.760km in medium rich water area, the maximum water inrush pressure is up to 2.6MPa, the maximum water inrush amount reaches 9000 ~ 9500m3/h, the working face collapses, the supporting structure is dehiscence and cracking, and the large-scale water inrush phenomenon is observed in the construction. Engineering problems are frequent and construction is very difficult and dangerous. In this paper, the mechanism and control technology of bad geological hazards in Guan Jiao tunnel are studied in depth, and the following research results are obtained.
(1) starting with data investigation and engineering practice, the water inrush mechanism of Guan Jiao tunnel is studied by qualitative analysis method. The water supply of water inrush is defined by means of flow test and Unicom test. Based on the geological data of typical case of inrush water, advance prediction data and design application situation, the hydrogeological model of Guan Jiao tunnel is summed up. According to the characteristics of karst development in Guan Jiao tunnel and the water gushing and drainage characteristics of the long distance reverse slope well, the water gushing pattern of the palm face and the cave body is put forward. According to the mechanism of the water inrush mode, the corresponding treatment measures are put forward according to the theoretical analysis and the numerical calculation method. Finally, a set of special tunnels suitable for the northwest karst area is formed. Comprehensive prevention and control technology of water gushing.
(2) using the method of experience summary and field test, it is pointed out that the water pressure distribution law of the fissure dissolving water action on the two lining has the characteristics of local high pressure and long-term increase. The load structure model is established by ANSYS to study the force of the straight wall and the lining of the curved wall form of the standard design map of the railway single line tunnel under the action of local water pressure. The characteristics and safety are analyzed and the effect of the lining safety factor is analyzed. The design parameters of lining under local high water pressure are put forward, which fills the shortage of lining design in the obvious stratum of local water pressure.
(3) through the investigation and experience summary, the influence degree of groundwater on the mechanical properties of rock mass is qualitatively analyzed. The revised regulations about the grade of the surrounding rock in the commonly used norms are summarized, the shortcomings in the standard are found and the suggestions for improvement are found. Through numerical simulation, based on the theory of fluid solid coupling, the stress distribution and deformation law of the underground water level, buried depth, initial support stiffness and supporting time are not at the same time with ABAQUS, which provide the basis for the mechanical response analysis of the surrounding rock support structure.
(4) based on the theory of loose ring, the design length of the bolt is obtained. Based on the theory of thick wall cylinder, the supporting characteristic curves of shotcrete, grid steel frame, steel frame and combined support system are obtained. Combined with the characteristics of supporting force, a water rich broken rock tunnel is put forward. The measures for the support of the road.
(5) in view of the instability phenomenon of the fracture zone, the mechanical properties of the supporting and surrounding rock are obtained by means of field test. According to the theoretical analysis of the test data combined with the theoretical analysis, the improvement measures are put forward. The numerical model is established by using FLAC3D to demonstrate that the improved scheme can effectively restrict the deformation of the surrounding rock and reduce the damage of the surrounding rock. The possibility of the occurrence of the geological hazard. Based on the principle of ensuring safety, saving the cost and shortening the time limit, the longitudinal zoning radial grouting technique is proposed for the further optimization of the radial grouting method in the improved scheme. By means of numerical simulation, the three-dimensional elastoplastic model is established by FLAC3D, and three main design parameters of the longitudinal zoning are as follows: By calculating the distance between the grouting face, the length of the grouting section and the spacing between the grouting sections, a design parameter combination satisfying different deformation control effects is obtained.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U456.33

【参考文献】