Research On Dynamic Response Of Buried Pipelines Under Seismic Waves

Pipeline project, including oil, water and gas transmission pipeline etc., is animportant branch of the lifeline project,which constitutes the foundation of themodern society to keep normal operation and plays a very important role in oursocial life.Lots of important pipeline engineerings have been built or are beingbuilt.East-west gas transmission project is the longest, most invested natural gaspipeline engineering whose construction condition is the most complex in ourcountry at present.South-to-north water transfer project and oil pipeline engineeringdistributed extensively in the nation also play an important role in our economic life.The underground pipeline has a large geographical span, its geological conditionand surrounding environment are complex and China is a zone with widely distributedstrong earthquake,all of them determine a greater risk of underground pipelines,andsocial will suffer serious damage once leakage or rupture happens. How to ensure thesafe of underground pipeline in the future earthquake is an urgent problem for thedesign and management department,and it is also a hot topic for the earthquakeengineering in recent years.It can provide the basis for the underground pipelinedesign under seismic shock through analyzing and summarizing the law of pipelineresponse under earthquake, so the research of pipeline response under earthquake hasgreat significant.Some real underground pipeline seismic analysis models are established byusing the finite element analysis software of Abaqus,adopting viscoelastic artificialboundary and using equivalent wave input method to input the seismic shock.Thebasic response laws of the pipeline under the earthquake are studied and the responselaws under seismic shock of the factors of buried depth, diameter, thickness, pipespacing, the radius of curvature of the bended pipe, the angle between the directionof vibration and the tube axis are also analyzed.The results show that the axial strain peak absolute value increases with theincreasing of the pipeline embedment depth, but increase substantially withincreasing burial depth decreases to a certain depth, the basic no longer increases.The peak absolute value of axial strain decreases with increasing of pipe diameterand the pipeline wall thickness, the greater the underground pipeline diameter andthe thicker the wall, the better is the seismic performance. Axial strain peak is proportional to the logarithm of pipeline parameters (including the embedment depth,diameter, wall thickness).The seismic response of underground pipelines increasegradually with the increasing distance between two pipeline, the twin-tube parallel tothe laying of the seismic response is small compared to the single tube. The seismicresponses of the elbow compared to the straight tube are significantly different, thecurved portion of the straight transfer of parts of the reaction, the design should beconsidered. Axial strain of the absolute value of the peak stress increases with thevibration direction and the angle between the tube axis and smaller.