Seismic Fragility Formulations for Segmented Buried Pipeline Systems Including the Impact of Differential Ground Subsidence

Abstract

Though differential ground subsidence (DGS) impacts the seismic response of segmented buried pipelines and increases their vulnerability, there are no fragility formulations that estimate repair rates under such conditions found in the literature. Although physical models that estimate pipeline seismic damage considering other cases of permanent ground subsidence (e.g., faulting, tectonic uplift, liquefaction, and landslides) have been extensively reported, this is not the case for DGS. The refinement of the study of two important phenomena in Mexico City—the 1985 Michoacan earthquake and the sinking of the city due to ground subsidence—has contributed to the analysis of the interrelation of pipeline damage, ground motion intensity, and DGS. From the analysis of the 122 cm (48 in.) diameter pipeline network of the Mexico City water system, fragility formulations for segmented buried pipeline systems for two DGS levels are proposed. The novel parameter