A review of advanced detection methods for tunnels and roadways

Abstract With the continuous development of underground engineering construction, a large number of tunnels and roadways need to be excavated every year in the world. However, the underground geological conditions are complex and variable; if not accurately identified in a timely manner, this can lead to various accidents and casualties. Therefore, accurate identification and advance prediction of adverse geological conditions ahead of tunnels and roadways are of great significance. This paper reviews the development process of advanced detection technology for tunnels and roadways, categorizing it into four stages (manual stage, automatic stage, detection while excavation stage, and intelligent stage), and China is currently transitioning from the second to the third stage. Additionally, this paper emphasizes the principles, characteristics, and applications of various conventional advanced detection methods, including seismic methods, electrical methods, electromagnetic methods, etc. And in response to the problems of short detection distance (maximum detection distance of 120m), low detection efficiency, and high cost of conventional advanced detection methods, the integrated design of the detection instrument and the tunnelling machine for advanced detection while excavation methods have been introduced, mainly including tunnel seismic while drilling (TSWD) and tunnel electrical while drilling (TEWD). The advanced detection while excavation methods can achieve coordinated excavation and detection operations, which can improve work efficiency by more than 50%, and the maximum detection distance of TSWD can reach 200m. In addition, this paper provides a unified summary of the advantages, disadvantages, and applicable conditions of conventional advanced detection methods and advanced detection while excavation methods. Finally, this paper discusses two important directions for the future development of tunnel and roadway advanced detection: multi-source signal cooperative detection and application of intelligent technology.