ABSTRACT
Long and deep tunnels often encounter geological challenges during construction, particularly in complex geological zones. These difficulties include water influx, the entry of toxic gases into the tunnel, convergence of the tunnel surrounding rocks, swelling, tunnel roof collapse, raveling, settlement of the ground surface, and high abnormal wear of cutting tools. Most of these events occur in fault zones, especially in wide broken zones associated with large faults. Therefore, understanding faults and predicting their behavior during the construction and operation of tunneling projects is important. Accurately predicting these behaviors, especially in mechanized projects, can be very effective in preventing delays and increasing time and cost. In this paper, an attempt has been made to present the lessons learned from studying the actual effects of mechanized tunnels that have encountered the most important faults in Iran. The results of this study can be used to evaluate the reliability of new models proposed by authors for classifying geological hazards in fault zones.
