Combined use of active and passive surface waves in the deep overburden area

The overburden thickness of the river bed is deep in southwestern China,and it is important to rapidly obtain the S-wave ve-locity of foundation site in hydropower engineering survey.Due to its low cost and simple operation,surface wave method has been widely used to detect shallow structure by S-wave velocity.In this study,the authors used active source and passive source surface wave methods to obtain S-wave velocity on the hydropower station dam in southwestern China.The active source surface wave method conducts detec-tion with high resolution,and the passive source surface wave method gives a deeper investigation.They have their own advantages re-spectively.