Towards robust fragility relations for buried segmented pipe in ground strain areas

• Published in: Earthquake spectra Vol. 31; no. 3; pp. 1839 - 1858
• Main Authors: O'Rourke, Michael, Filipov, Evgueni, Uckan, Eren
• Format: Journal Article
• Language: English
• Published: Earthquake Engineering Research Institute 01-08-2015
• Subjects: Asia; Damage; deformation; Earthquakes; elastic waves; Engineering geology; engineering properties; faults; Fragility; geologic hazards; ground motion; Grounds; Izmit earthquake 1999; Izmit Turkey; Kocaeli Turkey; liquefaction; Middle East; natural hazards; Pipe; Pipelines; propagation; seismic waves; Seismology; Strain; strike-slip faults; Turkey; Wave propagation; MED, Turkey
• DOI: 10.1193/032311EQS076M
• EISSN: 1944-8201
• ISSN: 8755-2930

Seismic fragility relations of buried segmented pipelines are currently defined in terms of pipe repairs per unit length as a function of some measure of ground shaking or ground movement. In some current relations, both wave propagation (WP) and permanent ground deformation (PGD) damage are addressed by combining the hazard into a measure of ground strain. One troubling aspect of these fragility relations is that each new event seems to provide new data that in some cases, are significantly different from existing relations. Herein, we investigate the robustness of these expressions by using new data from the 1999 M = 7.4 Turkey earthquake. A methodology is presented to calculate ground strains, by considering relative PGD along the axis of the pipeline. Results indicate that, for the strain/damage range of interest, a linear function (on a log-log scale) provides a relatively robust fragility relation for buried segmented pipes.