Unknown and difficult to detect buried utilities within the right-of-way (ROW) pose significant challenges for highway construction projects. Discovering these utilities during construction can lead to project delays, change orders, additional subcontractor charges, and potential safety or environmental hazards, especially if hazardous materials are involved. The current practice of conducting utility investigations involves using ground-penetrating radar (GPR), among other geophysical techniques, to locate buried utility facilities. However, GPR's effectiveness is soil-dependent, and the signal penetration depth into the earth varies with soil characteristics. Recent advancements in array-based GPR technology have improved data gathering through enhanced electronics, though challenges remain in certain soil types like clay. This study presents an analysis of data collected using a multi-channel GPR (MCGPR) system across 36 sites in Texas. Data collection sites were selected by identifying oil and gas pipeline crossings based on the Railroad Commission spatial database and sites exhibiting a wide range of suitability levels on the GPR soil suitability map from very high to very low penetration. The analysis of GPR data shows an increase in pipeline detection with increasing GPR soil suitability. However, in some exceptional cases, the GPR system failed to locate utility crossings in high-penetration zones but successfully identified them in a few low-penetration zones. This study summarizes the best practices and lessons learned from GPR data collection in Texas and processing to find buried utility facilities.
Shukla et al. (Thu,) studied this question.