综合物探法在隧道超前预报中的应用效果分析

发布时间：2018-09-12 08:28

【摘要】：隧道建设一直是我国发展交通和市政建设的大头,在地形条件较差和地质构造复杂的地区,断层带、褶皱、节理裂隙等构造比较发育,地下水丰富,隧道围岩所处的工程地质条件较差,增加了隧道施工难度和危险,面临的施工难题也日趋复杂,因此如何提高复杂地区隧道超前预报的准确性已经成为迫切解决的课题。本文通过理论数值模拟分析和现场试验方法,结合工程验证,对复杂地质区隧道的综合物探预报技术做了研究,旨在提高隧道的超前预报准确性。本课题具体的研究内容和所取得的成果为:(1)结合隧道常见的岩溶、断层、煤层瓦斯的地质灾害特征和国内外研究现状,对隧道地质超前预报的各种方法特点进行了分析,阐述了选择TSP法和地质雷达法作为综合预报方法的优点及可行性。通过分析单一物探方法的局限性,对比综合物探技术在排除单一方法多解性中的优越性。根据复杂隧道地质灾害的危害和成因不同,通过对隧道超前探测的存在的预报技术对比研究,发现地质雷达法和TSP法能够相互印证,发挥各自的特点,取长补短,为隧道施工提高可靠的技术支持和保障。(2)研究了TSP超前预报方法的工作原理和观测系统,通过自己写代码模拟了在隧道全空间地震波的传播特征和响应特征,并对隧道预报中常见的断层、空洞以及充填型溶洞等地质灾害的弹性波特征做了数值模拟,从而弥补了在隧道地下空间的地震波资料有限的缺点,通过实测资料的对比,判断其合理性和可行性。正演模拟结果结合实测典型异常区的图像特征收集,对比已有的软件解释依据和方法,参考典型灾害异常区的隧道TSP反射层位与物理力学参数二维成果图,通过成果图像列举,总结了TSP法在隧道超前预报的解译标志。(3)研究了探地雷达的工作原理、观测方式和资料解释方法,运用Gpr Max正演模拟软件,对隧道异常区的地质雷达勘探进行了有针对性的数值模拟,主要从岩溶空洞、含水溶洞、掌子面前方断层等几个不同特征着手,丰富了在隧道岩溶和断层方面雷达资料有限的缺点,通过实测图像的比对,判断其合理性和可行性。正演模拟结果对比实测地质雷达异常区的电磁波特征收集,总结并完善了地质雷达法在隧道超前探测中的判识准则,从而辅助技术人员来识别不同异常区的形态和特征。(4)通过对地质雷达和TSP综合物探技术在同一隧道岩溶超前预报中的应用效果分析,发现TSP的预报法的探测距离长,对于软弱、断层破碎带岩性界面等面状构造探测效果好,对不规则形态的三度地质体,如溶洞、暗河等不良地质体探测效果较差;而地质雷法对短距离探测精度高,对充水、充泥、空腔以及不规则三度地质体(溶洞、暗河)探测效果好。结合前期的工程地质资料,采用TSP法和地质雷达法这种长预报与短预报相结合、面状构造预报与不规则地质体预报相结合的模式,能够对隧道灾害地质体的具体位置和特征进行准确、可靠的预报,预报结果能够满足岩溶隧道的安全施工要求。
[Abstract]:Tunnel construction has always been a major part of the development of transportation and municipal construction in China. In areas with poor topographic conditions and complicated geological structure, faults, folds, joints and cracks are well developed, groundwater is abundant, and the engineering geological conditions of the surrounding rock of the tunnel are poor, which increases the difficulty and danger of tunnel construction, and the construction problems are increasingly complex. Therefore, how to improve the accuracy of tunnel prediction in complex areas has become an urgent problem. In this paper, through theoretical numerical simulation analysis and field test methods, combined with engineering verification, comprehensive geophysical prediction technology of tunnel in complex geological areas is studied, aiming to improve the accuracy of tunnel prediction. The research contents and achievements are as follows: (1) Based on the characteristics of geological hazards of karst, faults and coalbed methane common in tunnels and the research status at home and abroad, the characteristics of various methods for tunnel geological advance prediction are analyzed, and the advantages and feasibility of selecting TSP method and GPR method as comprehensive prediction methods are expounded. The limitation of single geophysical prospecting method is compared with the superiority of comprehensive geophysical prospecting technology in eliminating the multiple solutions of single method.According to the different hazards and causes of geological hazards in complex tunnels,through the comparative study of the prediction technology for the existence of tunnel advanced detection,it is found that the geological radar method and the TSP method can verify each other,display their respective characteristics and acquire their advantages. (2) Study the working principle and observation system of TSP advance prediction method, simulate the propagation characteristics and response characteristics of seismic waves in the whole space of tunnel by writing code, and give the elasticity of common geological disasters such as faults, cavities and filling karst caves in tunnel prediction. Wave characteristics are simulated numerically to make up for the shortcoming of limited seismic data in underground space of tunnel. The rationality and feasibility are judged by comparing the measured data. The forward simulation results are combined with the collection of image features of typical anomaly areas, and the existing software interpretation basis and methods are compared with reference to typical disaster anomaly areas. TWO-DIMENSIONAL RESULTS MAP OF TSP REFLECTION HORIZONE AND PHYSICAL AND MECHANICAL PARAMETERS OF TUNNEL AND THE INTERPRETATION MARKS OF TSP METHOD FOR TUNNEL PREDICTION are summarized by enumerating the results of the images. (3) The working principle, observation method and data interpretation method of ground penetrating radar are studied. The numerical simulation of karst cave, water-bearing cave and faults in front of the face enriches the shortcomings of limited radar data in tunnel karst and faults, and judges its rationality and feasibility by comparing the measured images. Collecting, summarizing and perfecting the criterion of GPR method in tunnel advance detection, so as to assist technicians to identify the shape and characteristics of different anomaly areas. (4) By analyzing the application effect of GPR and TSP comprehensive geophysical prospecting technology in the same tunnel karst advance prediction, it is found that the detection distance of TSP method is long. The weak fault fracture zone lithologic interface isosurface structure detection effect is good, the irregular shape of the third-degree geological bodies, such as caves, dark rivers and other bad geological bodies detection effect is poor; and the geological lightning method for short-range detection accuracy, filling water, filling mud, cavity and irregular third-degree geological bodies (caves, dark rivers) detection effect is good. The combination of long-range forecast and Short-Range Forecast by TSP method and GPR method, and the combination of surface structure forecast and irregular geological body forecast can accurately and reliably predict the specific location and characteristics of the geological body in the tunnel disaster, and the forecast results can meet the requirements of the safe construction of karst tunnel.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U452.11

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