摘要: |
This report contains the results of several projects that utilized nondestructive, geophysical methods. The purpose of the research is to determine successful applications of geophysics to geotechnical work and gauge the effectiveness of different methods. These methods include ground penetrating radar, shallow seismic reflection, electromagnetic induction (EM), and electrical resistivity. Geophysics successfully assessed roadway and subsurface conditions with nondestructive, continuous profiles. Case studies in this report address karst related voids and sinkholes, underground storage tanks, bridge scour, and abandoned underground mines. A protocol for evaluating the utility of ten commonly employed geophysical methods is provided in this report. This protocol serves as an aid to the highway engineer in the selection of appropriate methods for the target and site. The GPR proved to be of useful utility in profiling the shallow subsurface soil structure and the reflection seismic survey established the bedrock structure below. Electromagnetic induction proved useful for mapping underground tanks and utilities, while resistivity was used for mapping bedrock and searching for air filled voids such as caves. |