Institute of Geomechanics, Chinese Academy of Geological Sciences
Doi
Abstract
Objective The Plateau Railway, constructed along the Yarlung Zangbo suture zone on the Qinghai-Tibet Plateau, crosses the active Cuona-Woka Fault Zone. Coseismic surface rupture caused by the active fault leads to engineering breaks, tunnel deformation, and geological disasters; it poses a significant geological safety risk during railway operation. Methods Based on remote sensing, field investigation, and published research, this paper analyzes the development characteristics, activity, and impact of the Cuona-Woka Fault Zone on the Plateau Railway that it intersects. Results The study shows that the Cuona-Woka Fault Zone consists of five northeast-trending branch faults. The western boundary faults of the Woka Basin (F2-1, F2-2) show Late Pleistocene activity, the eastern boundary faults of the Woka Basin (F2-4, F2-5) have Holocene activity, and the F2-3 fault within the basin is the seismogenic fault of the 1915 MS 7.0 Sangri earthquake. Based on the deformation signs caused by fault activity and the types of active faults, it is estimated that future coseismic surface ruptures of the branch faults of the Cuona-Woka Fault Zone may cause deformation and damage to the Zangga tunnel and the Sangzhuling tunnel, which cross the fault zone, with an impact width of approximately 16~30 m. Conclusion Therefore, it is recommended to strengthen research on geological safety risk prevention measures for strong seismic deformation and engineering breaks in the sections of the Plateau Railway crossing the active fault zone. [Significance] The results of the study provide guidance for safe operation and disaster prevention and mitigation of the Plateau Railway, as well as a reference for the impact assessment of active fault engineering on other railway lines
