Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

Electric power systems have critical importance in the sustainability of social life and economy. The past and recent earthquakes showed clearly that these systems have high vulnerability due to earthquakes. In this study, the typical electric power systems which are commonly preferred and located at five different sites in high seismic zone of Turkey, Marmara region, have been examined. In the first part of the study, the earthquake hazard for Marmara region has been accomplished. The earthquake hazard curves at five different sites for two different earthquake levels, and two different site conditions as soft and stiff site classes according to the Turkish Building Seismic Design Code 2018 have been obtained. The seismic vulnerability assessment of substation and distribution circuits for two different design states, namely anchored and unanchored, achieved by the fragility functions. The probability of power outage durations have been evaluated based on the restoration curves. It has been observed that the results obtained within the scope of the study are highly consistent with post-earthquake studies in the literature. The proposed methodology through the power outage graphics enable a quick preliminary evaluation of the power outage based on the current design status and location for any electric power systems in the Marmara region.