Seismic Response Analysis Of Prefabricated Urban Utility Tunnel

The utility tunnel,a highly intensive urban infrastructure,centralizes the water supply and drainage,cable,communication,gas,heat and other municipal pipelines.It is an effective measure to solve the contradiction between pipelines and space in the future urban development.With the rapid development of our country,the development and construction of the utility tunnel have been strongly supported.However,there is no specific anti-seismic design criterion for the utility tunnel.In terms of the seismic study of the utility tunnel,there are few seismic response analyses for the prefabricated utility tunnel with joints.In order to analyze the response of the prefabricated utility tunnel under earthquake excitations,the three-dimensional finite element model of the utility tunnel was built by numerical simulation.The seismic response analysis of the prefabricated utility tunnel was conducted to study the response characteristics of the prefabricated utility tunnel under the influence of joint and the influence of different joint’s simulation methods.Reasonable suggestions were put forward for the seismic design of the prefabricated utility tunnel by summarizing the response characteristics.The researches of this thesis are as follows:1)The development of utility tunnel at home and abroad was introduced.And the characteristics of seismic damage,seismic research methods and research status of utility tunnel were summarized.The method of numerical simulation of the prefabricated utility tunnel was expounded.Such as the concrete damage constitutive model,the soil constitutive mode,the theory of soil-structure contact surface,three dimensional artificial boundary conditions and the input methods of earthquake ground motion.2)Based on the large finite element software of ABAQUS,the parameters of numerical simulation were determined combining the existing research result.A reasonable three-dimensional finite element model of prefabricated utility tunnel was built through numerical simulation analysis and the actual utility tunnel project.3)The effective seismic input method was determined by comparative analysis of three different directional earthquakes.The seismic response analysis was carried out for the prefabricated utility tunnel model without joint,summarizing the response law.It was found that the connection between side plate,partition plate and top(bottom)plate were the most vulnerable position.The earthquake ground motion of long period was selected to compare the calculation and analysis,so as to consider the effect of seismic difference.The influence of different support-pipe contact conditions on pipeline in the utility tunnel was studied.4)Comparing with the response of the prefabricated utility tunnel model without joints,the seismic response of two kinds of prefabricated utility tunnel model is analyzed.It was discovered that the concrete damage decreased,while the response of the pipe in the tunnel increased.Compared with buried pipeline,the stress peak of pipeline in the tunnel is greatly reduced.The analysis and research above used utility tunnel relative displacement,interlayer displacement angle,reference points acceleration,utility tunnel concrete damage and pipeline stress in the utility tunnel as the reference index for seismic performance.It is hoped that it could provide a reference for the seismic design of the utility tunnel.