An Application of Seismic Reflection Survey with Kra-Seaw Dam, Dan Chang District, Suphanburi Province

Abstract

This study aims to apply the seismic reflection technique's for the geological surveying and engineering inspection of the Kra-Seaw dam, Dan-Chang District, Suphanburi Province that was constructed over 30 years ago. This study began with the primary functions of collecting concerning information data, survey design, field surveying and data processing. In the field, seismic data were collected by Geode 24 and the Geophones frequency of 28 Hz that had been installed via land streamer cable. Pre-Stack Time Migration (PSTM) data processing techniques were used to process the survey data. This study found that the speed of the reflected waves that were generated by a sledgehammer gave data that suggests a depth of investigation around 60-70 meters, which is in the low-frequency band. Two groups of geological classes can be identified from the seismic section. The first group is a shallow ground layer, the reflected wave speed is between 400-800 meters/second. This group is the compacted soil layer formed into earth dam body. The second group is the deep layer, the reflected wave speed is between 900-1,200 meters/second, this group is a ground improved layer and basement layer and is the foundation of this dam.