Performance-Based Seismic Response of Continues Buried Steel Pipelines Under Near-Field Ground Motion Effects

Performance-Based Earthquake Engineering (PBEE) attempts to improve seismic risk through assessment and design methods that are more informative than current approaches. However, little work has been performed investigating the seismic response of buried steel pipelines within a performance-based framework. In this paper the seismic response of buried steel pipelines are studied in a performance-based context. Multiple nonlinear dynamic analyses of three buried steel pipes with different D/t and H/D ratios, steel grade and various soil characteristics carried out using an ensemble of near-field ground motion records were scaled to various intensities to capture the behavior of buried pipeline in the range of elastic response to dynamic instability. Peak axial compressive strain in critical section of the pipe was considered as engineering demand parameter (EDP) of pipelines. Several ground motion intensity measures (IMs) are considered to investigate their correlation with EDP. Using the regression analysis in logarithmic space the efficiency and sufficiency of investigated IMs are studied.Among the models investigated in this study it was seen that VSI[w1(PGD+RMSd)]^0.5 , PGV and SMV are the most sufficient IMS. For buried steel pipelines investigated in the studied it was concludede that PGD is the most sufficent IM for near-field fround motions. It was seen that VSI[w1(PGD+RMSd)]^0.5 followed by SMV are the optimal IM for buried steel pipelines under near-field ground motions based on both efficiency and sufficiency conceptions.