Seismic Response Analysis Of Underground Pipeline

Lifeline engineering is the basic facilities and system which is dispensable to human daily life and cities' economy functions. The lifeline engineering including region electric power and communication systems, water and gas transmission networks, news report system and so on. And these are essential for sustaining the life of community after a catastrophic event such as a destructive earthquake. With the increasing of underground pipelines and frequent earthquake damage, the importance and necessity of the seismic analyze for underground pipeline has been recognized in recent years. Furthermore, the vibration characteristics of underground pipelines are different from those of overground structures, so that the seismic analyze for underground pipelines has particular characteristics.The paper first analyzes the earthquake disasters of underground pipelines. According to earthquake information, the paper generalized the damage characteristic and effect factors of the underground pipeline.Then, finite element model of the underground pipeline is built by ANSYS finite element analysis program, firstly, the paper obtains the displacement and stress value of the structure by the static analysis, the static load include soil pressure, water pressure and etc.. Secondly, the paper compares the effect of different vehicular load on internal force of the pipeline structure. Next, by the modal analysis of the pipeline, the paper gets the natural frequency and cycle, calculates and analyzes the response of pipelines on the one-way seismic wave excitation.The paper studies the impacts of three types sites and seismic intensity, 15 earthquake wave are inputed totally, summarizes the response pattern of the different sites and intensity by comparing the calculation results:1. With the increasing of the earthquake intensity, the seismic response of the pipeline is intensified, and the intensity of earthquakes on the pipeline is significant.2. Under different site conditions, response of the pipeline is different, and sometimes the site conditions have more impact on the pipeline than seismic intensity.3. The seismic performance of common reinforced concrete pipeline in the essay under the seismic loading is not very good. When the structure located in I site condition 9 seismic intensity, it will be tension cracked,so the seismic capacity of the pipeline should be improved. The calculated data and conclusions in this paper can provide some references for the seismic design of the buried pipeline.