地震映像法在沪昆高铁贵州段隧底岩溶探测的应用研究

发布时间：2018-03-09 10:19

本文选题：地震映像法　切入点：隧底岩溶探测　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：隧底岩溶的危害不仅仅体现在施工方面,如得不到及时整治处理或整治处理的不彻底,在后期运营工程中构成对隧道安全的威胁,危及行车安全,因此如何准确而有效的判定岩溶的发育区所在位置显得尤为重要。地震映像法是一种快速、无损的检测方法,并可结合地震反射波、折射波、绕射波等多波信息,实测数据的分析与解译相对简单。虽然该方法在隧底岩溶探测方面应用较少,结合本次工程探测实际,证明该方法应用效果良好,可有效查明隧底岩溶的分布情况。首先介绍了地震映像法检测的理论基础。地震波在成层介质中的分类、传播机理、时距曲线方程、弹性波动力学基础、弹性波波动方程、地震映像法的基本原理。再者介绍了有限差分的基本原理和大致流程。Tesseral软件就是建立在有限差分基础之上开发的商业化软件。采用Tesseral地震波模拟软件产生双道地震波,对其进行道集分离后,利用地震处理软件Vista对相同偏移距的地震波形记录进行叠加。得出了单层介质模型、空洞模型、低速体模型以及空洞充水模型的波场响应特征。最后对地震映像法的实测技术与影响因素进行研究,其影响因素主要包括激发条件、接收条件、耦合条件、偏移距因素、噪声因素等等。结合该方法在沪昆高铁贵州段的实际工程探测,得出了正常介质、溶蚀破碎带、空洞介质等地质体的波场响应特征,将作出的异常区域解译与实际资料进行对比,证明该方法在隧底岩溶的探测效果良好。地震映像法检测速度较快,穿透距离较大,虽然精度上有些误差,但作为一种快速无损探测方法,可基本满足工程要求。由于采用单一物探手段对隧底岩溶进行探测,存在误判的现象,需增强与工程实际的结合。
[Abstract]:The hazards of tunnel karst are not only reflected in the construction, such as not timely treatment or treatment is not thorough, in the later operation of the project constitutes a threat to tunnel safety, endangering the safety of driving, Therefore, it is very important to determine the location of karst development area accurately and effectively. Seismic mapping method is a fast and nondestructive detection method, which can be combined with seismic reflection wave, refraction wave, diffraction wave and other multi-wave information, such as seismic reflection wave, refraction wave, diffraction wave and so on. The analysis and interpretation of the measured data is relatively simple. Although the method is seldom used in the detection of karst at the bottom of the tunnel, it is proved that the method is effective in the application of this project. The distribution of karst in tunnel bottom can be effectively identified. Firstly, the theoretical basis of seismic mapping method is introduced. The classification, propagation mechanism, time-distance curve equation, elastic wave mechanics foundation, elastic wave wave equation of seismic wave in stratified medium are introduced. The basic principle and general flow of finite difference. Tesseral software is a commercial software developed on the basis of finite difference. The Tesseral seismic wave simulation software is used to generate double channel seismic waves. After the gather separation, the seismic waveform records with the same offset are stacked by the seismic processing software Vista. The monolayer medium model and the cavity model are obtained. The characteristics of wave field response of low-velocity body model and void-filled model are studied. Finally, the measured technique and influencing factors of seismic mapping method are studied. The influencing factors mainly include excitation condition, receiving condition, coupling condition, offset factor, etc. Combined with the practical engineering survey in the section of Shanghai, Kunming and Guizhou, the characteristics of wave field response of normal medium, dissolved broken zone, cavity medium and so on are obtained. By comparing the interpretation of anomalous region with the actual data, it is proved that the method is effective in detecting karst at the bottom of tunnel. The seismic image method is fast in detection and has a large penetration distance, although there are some errors in accuracy. However, as a fast nondestructive detection method, it can basically meet the requirements of engineering. Because the single geophysical method is used to detect the tunnel bottom karst, there is a phenomenon of misjudgment, so it is necessary to strengthen the combination with engineering practice.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U212.22;P631.4

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