EVALUATION AND PROPOSAL OF EMPIRICAL METHODS TO ESTIMATE SEISMIC RESPONSE OF PIPELINE

Longitudinal strain in pipeline has been reported to be significant design parameter for seismic design of pipelines. Very detailed dynamic and time history analysis can be performed to calculate the strain with a three-dimensional (3D) numerical model. However, there are a series of difficulties to perform the complicated 3D analyses in practice. In this article, guidelines which can predict the longitudinal strains of pipeline and be used in practice without performing a 3D analysis are proposed. For the guidelines, 3D time history analyses were performed in various conditions and earthquake motions, using the displacement time history curves calculated from a one-dimensional site response analysis. Compared with the results of 3D analyses, it is shown that a pseudo-static analysis may be used instead of a time history analysis to evaluate the seismic performance of pipelines and analytical solution has a limitation to simulate soil-pipeline interaction during earthquake. Based on these studies, correlation between the longitudinal strain and parameters for a pseudo static analysis were found and applied to proposed method for estimating the seismic response of pipeline conservatively. Additionally, it is evaluated whether the longitudinal strain can be estimated without even 1D site response analysis.Maste