工程地震折射波解释方法研究进展

地震折射波勘探是工程与环境地球物理中应用最为广泛的方法之一。作为一种简洁方便又经济实惠的勘探方法,它可为工程地质提供近地表地层起伏变化和速度横向变化以及潜水面变化资料等。随着工程地质勘查和城市地质勘探工作的发展,工程地震折射波法数据处理与解释变得尤为重要。本文主要介绍了浅层地震折射波法的发展历程、应用条件,并总结和讨论了几种主要折射波解释方法的原理。在此基础上,比较并讨论了各种方法在应用中的优势和不足,阐述了近年来国内外浅层地震折射波法的发展现状及趋势,并着重介绍了作为研究热点的折射层析成像方法。研究表明:当探测深度较浅且分界面足够平整、界面倾角较小时,最方便的解释方法是截距时间法;当勘探目标的深度达到25 m时,t0差数法最为适用;勘探目标埋深超过25m时,应当使用广义互换法。随着勘探精度要求越来越高,使用折射波走时层析成像技术可以满足纵横向速度变化的近地表地层,包括大倾角地层、隐伏层、界面起伏层等。

Progress of Engineering Seismic Refraction Interpretation Method

Seismic refraction exploration is one of the most widely used methods in engineering and environmental geophysics.As a simple,convenient and economical exploration method,it can provide the engineering geology with the fluctuation of the ground floor,the variation of velocity,and the variation of the diving surface.With the development of engineering geological and urban geological exploration,the data processing and interpretation of seismic refraction wave method is even more important.In this paper,w e mainly introduce the development history and application conditions of the shallow seismic refraction wave method,and summarize and discuss the principle of several main refractive wave interpretation methods.On this basis,we compare and discuss the advantages and disadvantages of various methods in the application,expounds the shallow refraction wave method at home and abroad in recent years,the development status and trend,and emphatically introduce the research focus as a method of refraction tomographic imaging.The research shows that when the detection depth is relatively shallow and the boundary of the interface is sufficient to smooth the angle of the interface,the most convenient interpretation method is the intercept time method;w hen the depth of exploration reaches 25 m,the t0difference method is most applicable;the generalized interchange method should be used w hen the exploration target is buried deeper than 25 m.As its high precision,the use of refraction wave traveltime tomography technology can satisfy the near-surface strata with horizontal velocity changes,including the formation of large dip angle,concealed layer,interface fluctuation,etc.