Detecting geological defects of the tunnels based on integrated geophysical techniques

Based on geological predictions of 21 tunnels on the Baise-Jingxi Freeway, this paper systematically analyzes and summarizes the performance of a combined use of three geophysical techniques (tunnel seismic prospecting (TSP), geological radar, and infrared exploration of water). Furthermore, two successful prediction examples were used to elucidate the application of the integrated geological prediction. The results indicated that, based on geophysical analysis, rational combinations of different geophysical techniques are more effective and accurate because each of them utilizes different principles and has its own merits. The statistical data of the geological predictions of the Bai-Jing Freeway verified the superior performance of the proposed approach. The prediction of faults and joint zones has an accuracy of approximately 72-90%. For karst caves, underground rivers and karst conduits, the accuracies are mostly in the range of 60-80%. The interpretation of surrounding rock classification can reach an accuracy of 80%.