전기비저항 탐사를 이용한 KTX 선로하부(150M) 공동지반 해석

Abstract

This study is to defined the applicability of a 2D electrical resistivity technique for the probing of underground cavities under KTX rail. At the test site, where the ground has subsided in the past, underground cavities are commonly found in the limestone bedrock, which is overlain with the alluvial deposits. The limestone cavities at the site are mostly filled with groundwater and clay; hence, they show levels of electrical resistivity that are significantly lower than those of the surrounding host bedrock. The dipole-dipole 2D resistivity survey were conducted along the KTX rail to define the developed cavities zones with 9 survey line. Then the analysis was applied to confirm the suspected cavities zones at 150m depth. The results of this study demonstrate that the zones of low resistivity correspond to the zones of the cavities, and recommended boreholes at the site. And 2D electrical resistivity survey is a very effective tool for detecting and mapping underground cavities in the karst area.