IDENTIFICATION OF 3D LATERAL VARIATIONS IN PSEUDO-3D MEDIUM USING SURFACE WAVE

The surface wave method is used for site investigation. Recently, using a multi-channel surface wave method (MASW) has become popular. The dispersion curve and inversion are typically estimated in these tests. The dispersion curve is less reliable in a laterally changing medium. Multi-offset phase analysis is introduced as a simple and powerful method for identifying lateral variations. This method can automatically identify the location of lateral variations by investigating the phase angle and its changes.A pseudo-3D medium is studied in this paper. Since regular surface wave methods (MASW) are not able to process 3D mediums, the site has modeled with several synthetic 2D models in two orthogonal directions. This was including six synthetic models implemented in this research. Due to the geometry of the medium, lateral variations of the medium in different models were observed at different locations. The location of lateral variations was identified in all models using phase offset diagrams. If there are lateral variations, considering the geometry of the ground and the synthetic models studied, these variations and their extension can be identified by repeating the tests in the medium using a multi-offset phase analysis of lateral variations.

Keywords:

Surface wave method , Lateral variations , Pseudo-3D medium , MASW