DISPERSION ANALYSIS Rayleigh waves
GEOLOGICAL STRUCTURE BELOW THE SURFACE
CASE STUDY: REGIONAL WHITE SAND DALEGAN GRESIK
GEOLOGICAL STRUCTURE BELOW THE SURFACE
CASE STUDY: REGIONAL WHITE SAND DALEGAN GRESIK
ABSTRACT
Seismic studies have been conducted to identify the structure of the bedding down the earth's surface by using one type of non-invasive method tests the Spectral Analysis of Surface Wave (SASW) through the analysis of Rayleigh wave dispersion. Rayleigh wave dispersion properties can be used to determine the structure of the earth based bedding shear wave velocity (Vs) against depth (h). Retrieval of data in this study are located in White Sand Dalegan Gresik regency by using forward and reverse shooting shooting
near offset offset of 5 meters and 38 meters far. From the results of data processing wave dispersion analysis Rayleigh on each path through the process of inversion of values obtained with the SASW method shear wave velocity (Vs) as a function of the depth of 103 m / s - 1763 m / s on a trajectory pertaman, 108 m / s - 1761 m / s for both the track and 103 m / s - 1761 m / s for the third track. So that from the shear wave velocity values are indicated at a depth of 0-5 meters structure pelapisannya form of dry sand and saturated sand, the depth of 5-10 meters of sand are not consolidated, the depth of 10-20 meters of porous sand and at a depth of 20 -55 meters porous clay and sandstone.
near offset offset of 5 meters and 38 meters far. From the results of data processing wave dispersion analysis Rayleigh on each path through the process of inversion of values obtained with the SASW method shear wave velocity (Vs) as a function of the depth of 103 m / s - 1763 m / s on a trajectory pertaman, 108 m / s - 1761 m / s for both the track and 103 m / s - 1761 m / s for the third track. So that from the shear wave velocity values are indicated at a depth of 0-5 meters structure pelapisannya form of dry sand and saturated sand, the depth of 5-10 meters of sand are not consolidated, the depth of 10-20 meters of porous sand and at a depth of 20 -55 meters porous clay and sandstone.
Keywords: Dispersion curves, Rayleigh waves, SASW method, the shear wave speed
