Seismic Response Analysis Of Underground Utility Tunnel Net

The underground utility tunnel in city is a kind of long linear structure that can accommodate a variety of municipal pipelines,such as water supply,recycled water,rain sewage,communication,heat,electricity and natural gas.In recent years,the planning and construction of the utility tunnel network have gradually enlarged the scale and formed a network.Some areas in China are prone to earthquakes and the seismic hazard is an principal factor affecting the safety of the utility tunnel network which is an important lifeline engineering of the city.So it shows no delay to study the anti-seismic property of the utility tunnel network.And then,this article regards the utility tunnel project of public cultural service area of Zhengzhou city as the background and applies the numerical simulation method to analyze the non-uniform excitation seismic response of the utility tunnel network.The main research content is as follows:(1)The seismic hazard characteristic and anti-seismic research data of some domestic and foreign utility tunnel are collected and the existing anti-seismic research methods of the underground structures are summarized.(2)It expounds the basic theory of the dynamic analysis of the utility tunnel network.On the basis of comparing three interaction models which include the beam elastic foundation model,the soil spring model and the contact model of the utility tunnel and soil,a three-dimensional finite element model of the utility tunnel network with connectors is established.(3)Selecting the El-Centro wave and inputing three different directions of earthquake uniform and non-uniform excitation,the article analyzes the deformation characteristic,displacement and internal force response of the utility tunnel network in different excitation and transmission.According to the extent of relative displacement which is on the both ends of interface in the utility tunnel,it could determine the weak position and failure pattern of the utility tunnel network and then confirm the most unfavorable excitation and transmission modes.(4)Adopt the variable-controlling approach,the article analyzes the influence law of seismic response of considering the vibrating direction of seismic wave,apparent wave velocity of non-uniform excitation,seismic intensity levels,the earthquake ground motion characteristic and whether there are interfaces and so on for non-uniform excitation of the utility tunnel network.According to the internal force and relative displacement of interfaces time-history's peak distribution of the utility tunnel network in all position.By comparing data and summarizing characteristic,the anti-seismic property of the utility tunnel network is briefly evaluated.