| Urban utility tunnel is a new type of municipal pipeline laying system which can optimize the allocation of underground space and improve the urban environment.With the development of urbanization and the use of green buildings,as a new prefabricated structure,corrugated steels have broad application prospects in the construction of utility tunnels.As a lifeline project,the utility tunnels should be designed to resistant earthquake.At present,the seismic researches of utility tunnels all over the world mainly focus on concrete structures,and researches of corrugated steel mainly focus on the static field.On the basis of an actual corrugated steel urban utility tunnel prototype structure,considering the interaction between soil and steel structure,the thesis systematically studies its seismic performance by combining the shaking table test and the numerical simulation.The main contents are as follows:(1)The thesis collects the development history and research status of utility tunnel all over the world,summarizes its characteristics of seismic damage and elaborates the necessity of seismic research on utility tunnels.This thesis also summarizes the research methods of considering the soil-structure interaction in the seismic design of underground structures.The effects of the interactions on the underground structures are elaborated,which builds a theoretical foundation for the research of seismic performances of utility tunnels.(2)The time history analysis method in ABAQUS was used to analyze the seismic performances of the corrugated steel utility tunnels.The results were compared with shaking table tests’ results.The results of numerical simulations and experiments agree well in the time history of acceleration.The acceleration amplification coefficient and its Fourier amplitude spectrum are consistent,which verifies the rationality of the finite element model.From the acceleration amplification coefficient,frequency spectrum analysis and earth pressure distribution,we found there is a significant interaction between the utility tunnels and the soil under the action of earthquakes.(3)Using the reasonable numerical model,the mechanism of the interaction between the utility tunnels and the soil was analyzed by changing parameters such as burial depth,site conditions,contact surface model and direction of seismic excitation.Combined with the domestic and foreign standard seismic design methods,using the results of shaking table tests and numerical simulations,we proposed a seismic calculation method for utility tunnels considering soil-steel interaction.At last we gave a case example to prove it. |
