EVALUATION OF TEHRAN PROVINCE GAS DISTRIBUTION PIPELINES DURING LIQUEFACTION

Overall performance of oil and gas pipeline networks during past earthquakes has been observed to be relatively good; however catastrophic damages have also occurred in some particular cases, mostly due to poor soil conditions and instabilities. Among these cases of soil failure, liquefaction in loose sandy soils with high ground water level has been a major cause, which makes this phenomenon a potential source of disruption for buried pipeline networks. In this study, the effect of liquefaction on both 250 and 60 psi gas distribution pipelines of Tehran Province has been studied. The studies show that no buoyancy will occur in the pipelines. Moreover, the effect of lateral spreading is negligible for Tehran gas network, but the settlement due to liquefaction in the southeast of Tehran has some major effects on local buried pipelines