SEISMIC WAVE PROPAGATION EFFECTS ON STRAIGHT JOINTED BURIED PIPELINES

The behavior of straight jointed buried pipelines subjected to seismic wave propagation is investigated. A realistic model is developed for the seismic response analysis of straight jointed buried cast-iron pipes with lead-caulked joints and ductile iron pipes with rubber-gasketed joints. The model takes into consideration the non-linearity as well as vari ability of the pipeline and ground characteristics. The results of the analysis under seismic wave propagation indicate that variability can have a significant influence upon response parameters. The seismic vulnerability of these pipes is examined as a function of the seismically induced ground strain. The effects of ground rotation are found to be negligible. Such a vulnerability analysis made it possible to develop estimation of damage ratios due to a joint pull-out failure mode. These estimates are benchmarked against observed damage to water systems and are found to yield reasonable results.