Abstract: For the safety and efficiency of roadway or tunnel construction in complex geological conditions， effective and accurate forward-prospecting technologies are required to detect unexpected geological conditions in front of tunnel face. Seismic exploration is one of the most important methods among all forward-prospecting technologies because of its advantages in detection distance and the interface recognition effect. Reverse-time migration （RTM） is an imaging theory to accurately describe the geological structure based on seismic forward-prospecting data. It can greatly improve the accuracy of detection when RTM is used in tunnel-based seismic forward-prospecting technology. In RTM， especially in the complex environment such as tunnel or roadway， the selection of imaging conditions and the strategy to suppress the low-frequency noise are the key to ensure the quality of imaging results. Based on the seismic RTM method， three typical geological models are constructed to compare the efficiency of several RTM imaging conditions and low-frequency noise suppression methods. The results show that the cross-correlation imaging condition based on Poynting vector is the most suitable imaging condition for seismic reverse-time migration in roadway or tunnel environment. The above study results provides a basis for the real application of RTM in tunnel-based seismic forward-prospecting technology.

Key words: advanced geological prediction of roadway, seismic reflection method, reverse-time migration imaging, imaging condition, low-frequency noise