Application of seismic refraction tomography for detecting a hidden potential fault

Abstract

Seismic refraction technique is an increasingly useful geophysical tool for geotechnical studies in civil engineering work including the mapping of different soil formation of subsoil and detection of the bed rock. Additionally, wave velocity is a key parameter which correlates directly with significant geotechnical parameters of soils and rocks. Today, the evolution of the measurement technique in the field and the data processing allows to obtain tomographic images which increases its potential for applications to evaluate structuration of rock mass. This work describes the basic principles of seismic tomography and a case history of an application in civil works used to evaluate the foundation conditions of a site were a new structure for a spillway for the Gatun lake, north Panama, was projected. The study allowed to detect a destructured band sector in the bedrock which was covered by more modern sediments and vegetation just in the site of interest for the foundation of a project. The magnitude of the destructured bedrock forced to relocate the structure.

Keywords

• wave velocity
• seismic tomography
• material characterization