三分量微动探测新方法研究

The purpose of this project is to develop a new method of geophysical exploration by simultaneously measuring S wave velocity structures and anisotropy parameters of the subsurface media at shallow depth for geological survey in urban areas - - - - three-component microtremor exploring technique. The advantages of this method are that: (1) the dispersive curves of Rayleigh wave and Love wave can be measured independently, then the data are used to calculate Vsv and VsH with the depth by inversion for obtaining the anisotropy parameter; (2) The limited number (M) of geophones in a circular array that may influence on the microtremor exploring results has been taken into consideration. This project highlights that it combines theoretical research, data acquisition system configuring, data processing and interpretation software engineering, field verification of the measured results in situ and popularizing its application, which makes its contribution to development of the techniques of geophysical exploration for geological survey at shallow depth in urban areas of China.

本项目的研究目的是发展一种能同时测量地下介质S波速度结构和介质各向异性参数分布的城市浅层地球物理勘探新方法- - - - 三分量微动探测技术。该方法的优点是：（1）能独立测量瑞雷波和勒夫面波的频散曲线，经反演求出Vsv和Vsh随深度分布，获得介质各向异性参数；（2）并考虑了在圆形台阵上采用有限个数（M个）检波器对结果的影响。本项目的研究亮点是理论研究、数据采集系统配置、资料处理解释软件、试验场地实测结果检验以及推广应用相结合，为发展我国城市浅层地球物理勘探做贡献。

目前基于台阵技术的微动探测方法仅利用瑞雷波频散信息，仅能获得介质的S波速度结构。本项研究发展基于三分量微动数据的瑞雷波和拉夫波频散信息提取及联合反演方法，从而能同时测量地下介质S波速度结构和介质各向异性参数分布，提高反演解的可靠性、降低非唯一性。实测结果显示对浅层不均匀块体的分辨有显著提高。本项研究对了解地下介质的物性组成具有重要意义，可望在我国城市浅层地球物理勘探中发挥重要作用。