岩溶隧道修建风险评估及关键参数研究

发布时间：2018-05-26 03:04

  本文选题：岩溶隧道 + 风险评估　； 参考：《重庆交通大学》2014年硕士论文

【摘要】：西部地区尤其是西南地区的公路隧道建设过程中，不可避免要遇到岩溶地质条件。在当今对安全施工和生态环境保护高要求的条件下，在岩溶地区修建隧道存在很多技术性难题。岩溶隧道修建风险评估与预警、防治对策以及溶洞和隧道间岩层的最小安全厚度关键参数成为不可忽视的问题，需要开展深入研究。 本论文依托万利高速公路长安寨隧道，采用资料调研、理论分析、数值分析等研究方法，主要研究内容包括：运用层次分析法和模糊综合评判理论对岩溶隧道水害风险进行评估，，得出岩溶隧道水害风险等级，根据风险评估等级确定出其对应的预警级别，并制定出不同预警级别的预控对策；运用ANSYS软件建立溶洞—隧道模型，研究不同位置溶洞和隧道之间岩层的最小安全厚度，并针对不同溶洞跨度、不同溶洞高跨比对溶洞和隧道之间岩层最小安全厚度进行数值分析，总结出它们之间的影响规律。 通过以上的分析研究，主要得出以下结论： ①岩溶隧道水害主要受到岩溶发育程度与蓄水构造的控制，其突水风险可分为四个等级，其中，Ⅰ级风险最高，Ⅳ级风险最低。 ②对应水害风险评估等级，岩溶隧道突水突泥预警级别可分为四个等级，分别用红色（Ⅰ级，最严重）、橙色（Ⅱ级，严重）、黄色（Ⅲ级，较重）、蓝色（Ⅳ级，一般）四种颜色表示。 ③对于岩溶隧道的防治，首先要重视超前地质预报，切实落实监控量测工作，备足抽水等应急设备，要制定逃生应急预案，遇到可溶岩与非可溶岩接触带时，要采用管棚、小导管、预注浆等手段对围岩进行预支护。 ④对于溶洞跨度，无论溶洞位于隧道哪一侧，隧道和溶洞间岩层最小安全厚度均随溶洞跨度增大而增大。 ⑤对于溶洞高跨比，无论溶洞位于隧道的哪一侧，当溶洞向着水平或垂直方向发展时，溶洞和隧道之间岩层所需要的最小安全厚度逐渐增加；当溶洞高跨比趋近于1.0时，即溶洞形状接近圆形时，溶洞和隧道间岩层所需最小安全厚度逐渐减小；当溶洞高跨比等于1.0时，即溶洞形状为圆形时，溶洞和隧道之间岩层最小安全厚度最小。 ⑥隧道侧面溶洞对溶洞和隧道之间岩层最小安全厚度影响最大，其次是底部溶洞。
[Abstract]:In the process of highway tunnel construction in western region, especially in southwest area, karst geological conditions are inevitable. Under the condition of high requirement of safety construction and ecological environment protection, there are many technical problems in constructing tunnel in karst area. Risk assessment and early warning of karst tunnel construction prevention countermeasures and key parameters of minimum safety thickness of karst tunnel and tunnel are problems that can not be ignored and need to be deeply studied. Based on the Changan Zhai Tunnel of Wanli Expressway, this paper adopts research methods such as data investigation, theoretical analysis, numerical analysis, etc. The main research contents include: using AHP and fuzzy comprehensive evaluation theory to evaluate the risk of karst tunnel water hazard, get the risk grade of karst tunnel water hazard, and determine the corresponding early warning level according to the risk assessment level. The pre-control countermeasures of different early-warning levels are worked out, and the cave-tunnel model is established by using ANSYS software to study the minimum safe thickness of rock layers between caverns and tunnels at different locations, and aiming at different caverns span, The minimum safe thickness of rock layers between caverns and tunnels is numerically analyzed with different ratio of height to span of caverns, and the influence law between them is summarized. Through the above analysis and research, the main conclusions are as follows: (1) the water hazard of karst tunnel is mainly controlled by karst development degree and water storage structure. The risk of water inrush can be divided into four grades, among which the first grade is the highest and the 鈪

本文编号：1935699