Seismic Isolation Analysis On Pipeline In Utility Tunnel

Utility tunnel belongs to one aspect of the lifeline engineering, normally refers to the structure which is built underground and contains more than 2 kinds of public facility pipelines or electronic wires, so does its attached structures. Since the economic situation is moving forward, the constructions of utility tunnels are started in many cities, and researchers are paying more and more attentions to the analyses on utility tunnels. One of the hottest topics is the work on seismic design theory and method of utility tunnel. This article started with the analysis on characteristic of seismic destruction of utility tunnels in different countries, then, based on the achievements in experiment and theory in lifeline earthquake engineering researching center in Harbin Institute of Technology(LEERC-HIT), using finite simulation program to analyze the seismic response regulation of pipeline in utility tunnel and the efficiency of seismic isolator, one seismic isolator design method which is proper for utility tunnels in China is proposed.Firstly, the way of load and destructive form are different between pipeline in utility tunnel and buried pipeline. In this article, normal damage of pipelines is listed, referring to isolation method of above-ground pipeline, effect factors to seismic response are discussed. Secondly, design one isolation method which is suitable to pipeline in utility tunnel.Thirdly, using finite element simulation program, different factors which can influence the response of pipeline in utility tunnel are analyzed.Lastly, comparing the results of simulation, this article concludes the efficiency of different factors, and one support seismic isolator is design.By analyzing the results of numerical simulation, it is shown that: earthquake response could be reduced with proper burial depth and friction force around pipe; reasonable spring stiffness with damping in the seismic isolator could bring proper isolating effects; laying fine sandy soil around structure of utility tunnel has obvious isolating effect.