岩溶隧道灾变分析及灾害防治研究

发布时间：2018-08-06 18:49

【摘要】：岩溶地区因受其特殊地质构造影响,在隧道施工过程中极易发生突水、涌泥等地质灾害现象,成为了制约隧道建设快速发展的瓶颈。因此本文针对岩溶隧道地质灾害,采用理论分析和数值模拟等研究方法,对岩溶隧道的灾变分析及灾害防治进行研究,得到如下结论：(1)总结岩溶产生的条件及分类,指出其发育的控制因素；阐述岩溶易导致隧道坍塌、岩溶突水、突泥等不良地质灾害。(2)立足岩溶隧道突水孕育时间长,破坏能量大的客观实际,将隧道的突水划分为能量积蓄和剧变失稳两阶段。基于力学分析,引入软化系数,得到了水对裂隙岩体强度的劣化计算公式。基于流体力学伯努利方程,得到了突水速度计算式,揭示了岩溶水压对突水量具有动力控制作用。将断裂力学理论方法运用于岩溶岩体在水作用下裂纹扩展研究,将裂纹扩展划分为拉剪扩展及压剪破坏模式,推导出充水条件下裂纹破坏的临界水压力值计算方法。(3)对岩溶隧道的突水灾变机理进行研究,重点分析了防突层灾变破坏及岩溶体结构面变形诱发灾变机理。基于能量分析,构建了尖点突变模型,得到了判别岩溶防突层以及岩溶结构面动力失稳的临界条件；用平衡曲面形象的刻画了动力系统演化过程中从一种状态到另一种状态的跳跃。通过对控制参数分析,揭示了蠕变控制因子对岩溶隧洞岩体软弱结构面演化速度的控制作用。(4)着重探讨了地质法、超前导坑法、地质雷达法和红外线探测法隧道的超前预报技术。通过理论分析并结合实际工程应用,提出了各种探测方法在施工应用中所应注意的问题。分别研究分小型溶洞及大型充填淤泥型溶洞处治技术,分别提出了相应处置措施,利用MDAS/GTS建立数值模型,数值模拟结果较好的论证了处治技术的合理性。
[Abstract]:Because of its special geological structure, karst areas are prone to water inrush, mud gushing and other geological disasters during tunnel construction, which has become a bottleneck restricting the rapid development of tunnel construction. Therefore, aiming at the geological hazards of karst tunnel, this paper studies the disaster analysis and disaster prevention of karst tunnel by means of theoretical analysis and numerical simulation. The conclusions are as follows: (1) summarize the conditions and classification of karst tunnel. The paper points out the controlling factors of its development, expounds that karst easily leads to tunnel collapse, karst water inrush, mud outburst and other bad geological disasters. (2) based on the objective reality of long gestation time and large destruction energy of karst tunnel water inrush. The water inrush of tunnel is divided into two stages: energy accumulation and sudden instability. Based on mechanical analysis and introducing softening coefficient, a formula for calculating the deterioration of strength of fractured rock mass by water is obtained. Based on the Bernoulli equation of fluid mechanics, the formula for calculating the water inrush velocity is obtained, and it is revealed that the karst water pressure has a dynamic control effect on the water inrush. The theory of fracture mechanics is applied to the study of crack propagation in karst rock mass under the action of water. The crack propagation is divided into tensile shear propagation and compression shear failure mode. The calculation method of critical water pressure for crack failure under the condition of water filling is derived. (3) the mechanism of water inrush in karst tunnel is studied, and the mechanism of cataclysmic failure of anti-outburst layer and deformation of karst structure surface is analyzed. Based on the energy analysis, the cusp catastrophe model is constructed, and the critical conditions for judging the dynamic instability of karst anti-outburst layer and karst structural plane are obtained. The jump from one state to another state in the evolution process of dynamic system is depicted graphically by equilibrium surface. Based on the analysis of control parameters, the control effect of creep control factor on the evolution velocity of weak structural plane of karst tunnel rock mass is revealed. (4) the geological method and the advanced guide pit method are discussed emphatically. Advanced prediction technology of tunnel with ground penetrating radar and infrared detection. Through theoretical analysis and practical engineering application, the problems that should be paid attention to in construction application of various detection methods are put forward. The treatment techniques of small caverns and large filled mud caverns are studied, and the corresponding disposal measures are put forward respectively. The numerical model is established by MDAS/GTS. The results of numerical simulation demonstrate the rationality of the treatment technology.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U452.1;U457

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