Seismic Response Analysis Of Typical Node Of Urban Underground Utility Tunnel

With the development of society,the traditional way of laying municipal pipelines and power grids has not been able to meet the concept of urban modernization.Urban underground utility tunnels have become a way to solve the current urban planning and development,and to enhance the overall image of the city,to create a harmonious ecological environment,which has played a positive role.At present,there are no special seismic codes for urban underground utility tunnels.Most of them refer to the similar projects and seismic codes of subways at home and abroad.As a result,there is a great potential danger in the structure of the utility tunnels,which may cause serious engineering damage and heavy loss of life and property when disasters happen.In this paper,by combining with practical engineering,using the finite element software,the dimensional viscoelastic boundary to establish a numerical model of typical joints of the soil structure interaction in utility tunnel,and analyze the seismic response of typical joints under the situation including horizontal,vertical and bidirectional coupling effects and the factors affecting the seismic response of underground utility tunnels,compare and analyze seismic respond under different conditions.And the seismic response and performance of utility tunnel joints under dynamic load are obtained,which can provide reference for the construction of utility tunnel.The results show that:the response of utility tunnel under bidirectional coupling and unidirectional excitation are similar.At the same time,it can be seen that the horizontal earthquake dominates the seismic response of utility tunnel.However,from the perspective of the use,service life,and the function in life,it is necessary to consider the most unfavorable combination of the three input ways to design the utility tunnel.In addition,the junction of the clapboard and the bottom plate and the middle plate are the weak parts of the utility tunnel,and maybe destroyed firstly under seismic load effect,which should be considered in design.At last,by analyzing the influence factors of utility tunnel from the lateral deformation,acceleration and equivalent peak in utility tunnel area.The results show that the force structure surrounding soil elastic modulus,peak acceleration of seismic wave,seismic wave spectral characteristics,considering the soil structure contact surface effect,soil structure contact surface friction coefficient of utility tunnel joints the seismic response has a greater impact,the concrete strength of structure has less impact.