瑞利波勘探中波长深度转换系数的探讨  

Discussion about the Wavelength-depth Conversion Coefficient in Rayleigh Wave Exploration

作　　者：杨天春[1] 陈永贵[2] 

机构地区：[1]湖南科技大学土木工程学院,湖南湘潭411201 [2]长沙理工大学岩土工程研究所,长沙市410076

出　　处：《勘察科学技术》2008年第2期26-30,共5页Site Investigation Science and Technology

基　　金：湖南省教育厅资助科研项目(06B030);湖南科技大学博士基金资助项目(E50607)

摘　　要：通过对该文两个特殊模型的模拟计算可知,尽管各层介质的瑞利波速度相等,但瑞利波还是存在频散现象。波速的变化说明,一定波长的瑞利波波速是一定范围内介质的综合反映;对于瑞利波速相等的两层介质模型而言,其波长深度转换系数并不随覆盖层厚度而变化;对于三层以上的层状介质而言,转换系数随各层介质厚度而变化,且各分界面的转换系数不同,一般浅层界面的转换系数大于深层界面的转换系数,实测结果也验证了该结论。可见,实际工作中采用半波长的解释方法肯定会造成一定的误差。研究适用的非线性反演方法是提高瑞利波勘探解释精度的必要途径。According to the forward modeling result, ＇although the velocities of Rayleigh wave are equal for each layer of the model, the dispersion phenomena still oecur. It illuminates that the penetrating depth of Rayleigh wave is finite. The conversion coefficient does not change for a two layers model in this paper. The conversion coefficients change for a three layers model, and they are different corresponding to different interfaces. The conversion coefficient of shallow interface is usually bigger than that of the deep one, and it has been proved by the measured result. It is obvious that it will induce some errors by haft-wavelength interpretation method in practice, and non-linear inverse methods must be studied in the future to enhance the prevision of exploration.

关 键 词：瑞利波 频散 导披模式 转换系数 

分 类 号：P631.4[天文地球—地质矿产勘探] TD166[天文地球—地质学]