Seismic behavior of a buried gas pipeline under earthquake excitations

Earthquake time-history analyses have been performed for a buried gas pipeline of API 5L Grade X65, which is popularly used in Korea. For this purpose, various parameters such as the type of buried gas pipeline, end-restraint conditions, soil characteristics, single and multiple earthquake input ground motions, and burial depths are selected. A comparative study has been performed to obtain the response characteristics of strains in a buried pipeline section, axial relative displacement, and transverse relative displacement. The capacity evaluation of the pipeline with respect to the response characteristics has been performed in comparison with the allowable strain and displacement capacity in axial and transverse directions, as suggested by the Guidelines for the Seismic Design of Buried Gas Pipelines, KOGAS. The present study is expected to provide useful information for an effective seismic evaluation of a buried gas pipeline.