三维地震勘探技术及其工程应用

Application of 3D seismic survey technique in engineering exploration

随着工程勘探要求的提高,如要查明地层结构的细微变化及地质构造等,采取常规二维地震勘探,在观测手段、信息、数据处理分析技术等方面受到制约。而高分辨率的三维地震勘探是在一定的面积上,以面的方式采集地下地震波信息。经数据处理后形成三维数据体(三维立体空间)进行多角度、多方位分析和解释,并可以多角度、多方位切片方式显示目的层,使成果分析和解释更加充分、详实。针对工程地球物理勘探的特点,介绍了三维地震勘探的相关技术,并通过某调水工程防渗线路探测的成功案例,证明该技术方法可在水利水电工程地质勘察中推广应用。

Seismic surwey has always been a primary method in geophysieal exploration due to its high accuracy. However, duo to increasing requirements on accuracy of engineering geological exploration such as detecting slight changes in strata eonfiguration and geological structure, regular 2D seismic survey technique is no longer effective because of some restricted factors of measuring methods, information, data processing. Underground seismic waves are collected in a section by section way through application of 3D seismic survey techniclue, and a 3D data body is formed after data processing, so that analysis and explanation can be con- ducted from different angles and positions in 3D space, and the target geological layer can be viewed in a certain section from dif- ferent directions, making the analysis and explanation more detailed and accurate. We systematically introduce the relevant 3D seismic survey techniques considering the features of engineering geophysical exploration, and by a successful case of anti - seep- age line detection in a water diversion project, to demonstrate that the 3D seismic survey techniques can be promoted and applied in the geological investigation of hydropower projects.