Preventive Structural Risk Assessment of Buried Gas Pipelines in Liquefaction of Ground

Recently, a number of earthquakes have been detected in Korea and damage has been reported. Actually, ground liquefaction was reported due to the earthquake that occurred in the Pohang. In Korea, the risk of liquefaction in the event of an earthquake is relatively higher as there are many landfill areas such as Busan's coastline, Incheon, and Cheongna International City. In this study, the effect of underground structures when liquefaction occurs is evaluated by dividing it into stages of liquefaction. Moreover, detailed evaluation methods for buried gas pipelines are presented in case of regional liquefaction that can be used in all regions. For the risk assessment of liquefaction, the Standard Penetration Test (SPT) result or Cone Penetration Test (CPT) result of the borehole is used. To evaluate buried gas pipelines, Finite Element (FE) analysis is performed using the subsidence calculation method linked with the borehole data. By defining ground and gas pipe variables, structural analysis is conducted in several cases, and the desired area is evaluated based on this. A Winkler foundation spring-based optimal finite element analysis model is developed to evaluate the structural seismic performance of gas pipelines across areas where liquefaction is expected.