Effect of Fault Crossing Angle and Location on Seismic Behavior of Transmission Tower-Line System

Transmission lines shoulder the important task of transmitting and distributing electrical power over long distances and inevitably cross active tectonic seismic faults when traversing seismic areas. Currently, very limited information is available regarding the seismic responses of fault-crossing transmission tower-line systems. In this investigation, a typical ultra-high voltage (UHV) transmission tower-line system model was developed in ABAQUS, and corresponding finite element (FE) analyses using six sets of bidirectional fault-crossing ground motion records were subsequently performed on the computer model to evaluate the effects of the fault-crossing angle (from 15 degrees to 165 degrees) and fault-crossing location (the midspan and side span of the system) on the seismic behaviors of the transmission tower-line system. The incremental dynamic analysis (IDA) method was utilized to investigate the collapse mechanism and overall collapse process of the system under different fault-crossing angles and locations. The results emphasized that the fault-crossing angle and location have a significant influence on the seismic response of the UHV transmission tower-line system crossing the fault. Moreover, the optimum layout of the UHV transmission tower-line system across a strike-slip fault was investigated based on the result comparisons. This study can provide a more comprehensive understanding of the seismic behaviors and the optimum layout scheme of fault-crossing transmission tower-line systems. Additionally, the lack of analyses and design guidelines for transmission tower-line systems crossing faults in international standards renders this research a useful reference for the field.