An Approach to model the soil shear wave velocity using the delay time of the converted SV

Paper ID : 1051-ISCHU

Authors

Amin Esmail Khalil * Helwan University

Abstract

Shear wave velocity determination at shallow depths is crucial to several Geotechnical studies. However, conducting a survey for shear wave modeling sometimes not feasible or the resolution is not sufficient. For instance, the multichannel analysis of surface waves MASW suffers from low resolution. The present work utilizes the principle of energy splitting at an interface to fill this gap. An incident P-wave at an interface between the soil layers and the bedrock will be converted to S-wave and bounce back to the surface. Since the seismic source is vertical for P-wave generation, the converted S-wave will be the vertically polarized shear wave. To receive this type of wave energy, the experiment adopts horizontal geophones that are aligned in the same with the source (longitudinal direction). Besides, the experiment utilized a transverse direction array to test any SH conversion. The amplitude of the reflected S-wave is controlled by the angle of incident of offset. Analysis is conducted to select the offsets of highest amplitude. At the current stage, the arrival times of the converted SV waves is compared against the arrival times of P. The delay time is used in order to model the average S- velocity of the soil layers.

Keywords

Shear wave velocity, converted SV wave, Hugh amplitude offset

Status: Abstract Accepted (Oral Presentation)