Study On Dynamic Response Of Buried Pipeline Across Site Under Seismic Wave

Pipeline engineering plays a key role in modern industrial production and people’s daily life,and pipelines that transport water,oil,gas,etc.are important cornerstones of today’s society.If the buried pipeline is damaged by earthquake,it may not only rupture or leak,but also may cause explosion,poisoning and other accidents,which will bring major disasters to the society and economy,and will also have a lot of adverse effects on the post-earthquake recovery.China has a large territory with complex topography and landform.The soil properties in different regions are different greatly,and the tectonic movement is more intense,so there are a large number of seismic zones,leading to strong earthquake disasters from time to time.Underground pipelines usually run through a wide area,often passing through different provinces,cities and counties,with the characteristics of large geographical span,complicated geological conditions passing through and surrounding environment.It is a common site condition that spans two types of soil.Therefore,it is of great significance to study the dynamic response law of cross-site buried pipelines under the action of seismic waves and to carry out relevant seismic damage research,,which is helpful to improve the operation state of underground pipeline and make it have higher safety and stability.Based on the current theoretical research status,with equal emphasis on centrifugal test and numerical simulation,relevant research was carried out on the dynamic response law of buried pipelines across the site under the action of seismic waves.First,the theoretical analysis method and numerical analysis method of buried pipeline were introduced in more detail.Then,with the buried pipeline as the research object,a centrifugal test model and a finite element model conforming to the real situation were constructed: A dynamic centrifugal model of buried pipeline was designed.The similarity relation of centrifugal test was used to make the model.Centrifugal model tests under multiple seismic intensification were carried out by means of the configuration of centrifuge and two-way independent vibration table inside the centrifuge,and the seismic response characteristics of pipelines under cross-site conditions were obtained;At the same time,the buried pipe was simplified into elastic foundation beam by using ANSYS finite element analysis software.The finite element model of cross-site buried pipeline was established by selecting beam188 beam element and Combin40 spring element.Reasonable mesh accuracy was set.By changing the parameters of the numerical model,as well as contrastively studying the influencing rules of pipeline-placed site conditions and seismic-wave-peak accelerated velocities upon buried-pipeline seismic responses.On this basis,the unitary regression model and multiple regression model of axial stress peak of buried pipeline are established to simplify the engineering analysis process.Finally,according to the results of the experiment and finite element analysis,combining the research theory with engineering practice,a targeted seismic measure was proposed to ensure effective protection of pipelines in design and construction,reduce or even completely avoid pipeline earthquake damage as far as possible,and bring more complete protection guarantee for the normal operation of buried pipelines and the overall safety of pipeline system.