Abstract: In order to meet the basic requirements of concrete gravity dam for foundation rock(it needs to be built on hard bedrock), it is necessary to find out the thickness and change of overburden above the top surface of foundation rock in the dam site area, and explore whether there are geological defects in the foundation rock. This paper introduces the application of geophysical prospecting techniques such as high-density resistivity method, seismic imaging method and Rayleigh wave method in the survey of dam foundation of a certain reservoir in Shanxi. The variation law of the thickness of the Quaternary overburden is basically found out, the weathering grooves in the rock of the dam foundation are revealed, and detailed technical data are obtained, which provides a reliable scientific basis for the design of the reservoir project. The example proves that rational use of technical advantages of various geophysical methods can achieve the effect of complement each other and mutual verification, so as to improve the reliability and accuracy of geophysical test results and escort engineering construction and safety.

Key words: reservoir dam, dam foundation survey, integrated geophysical prospecting, high density resistivity method, seismic imaging method, Rayleigh wave method

摘要： 为满足混凝土重力坝对坝基岩体的基本要求(需建在坚硬基岩之上),需要查明坝址区基础岩体顶面以上覆盖层厚度及变化情况,并探查建基岩体内部是否存在地质缺陷。文中详细介绍了高密度电法、地震映像法、瑞雷波法等物探技术在山西某水库大坝坝基勘测中的应用情况,基本查明了第四系覆盖层厚度的变化规律,揭示了坝基岩体中的风化凹槽,取得了翔实的技术资料,为水库工程设计提供了可靠的科学依据。该实例表明合理利用各种物探方法的技术优势,可以达到取长补短、相互验证的功效,进而提高物探测试成果的可靠性和准确性,为工程建设与安全保驾护航。

关键词: 水库大坝, 坝基勘测, 综合物探, 高密度电法, 地震映像法, 瑞雷波法