Study On Dynamic Response Of Pipe Gallery Under Impulsive Effect And Oblique Incidence

With the increasing demand of urban development,the construction scale of underground comprehensive pipe corridor is getting expanding,Seismic design of utility tunnel has increasingly become an important topic concerned by engineering.This paper describes the development of plans for the development of urban corridors in the country,outlines the characteristics and research methods of seismic response of underground structures.Taking the soil-structure interaction as the core,the input method of oblique seismic equivalent load input based on three-dimensional infinite element-finite element coupling is obtained by considering the traveling wave effect,the radiation damping of the foundation and the reflection of the seismic wave in the stratum.The method is applied to the seismic analysis of the underground pipe gallery structure,and to analyze the influence of oblique incidence on the structure.Selecting three groups of pulse earthquake,and synthesizing non pulsating earthquakes according to their response spectra.To compare the dynamic response of structures under impulsive and non-impulsive earthquakes earthquake,the influence of earthquake with impulse energy on underground pipe gallery is studied,and the results of buried pipelines and pipe tunnels are compared.The calculation results show that:(1)the equivalent load input method based on the three-dimensional infinite element can effectively simulate the propagation law of seismic waves in the infinite foundation,and the results in the semi-infinite foundation are in agreement with the theoretical solution.(2)The incident angle of ground motion has a great influence on the dynamic response of the underground pipe gallery.With the increasing angle of incidence,the dynamic response of the structure tends to increase in general,the uneven change of the foundation caused by oblique incidence will cause the structure to be in a complex state of stress,and more prone to be destroyed.Therefore,the influence of oblique incidence of seismic waves should be taken into account in seismic design analysis of underground pipe corridors.(3)In the case of the same acceleration,the dynamic response of the structure is greater than that the non-impulse earthquake.The impulse effect will enlarge the effect of the earthquake on the structure,so the pulse effect should be considered when designing the structure of the pipi galley.(4)According to the result of the stress,damage factor and relative displacement,it is easy to yield plastic yield on the top of the gallery,which is the weak link of earthquake resistance,and the top position should be paid attention to in the seismic design.And when seismic pulse effects occur,the structural dynamic response is maximized.(5)Inclined incidence of the earthquake will cause the internal pipeline to be in a complex state of stress.Unlike the structure,the response of the pipeline is greatest at 30 degrees.The stress of the pipeline inside the gallery is less than the direct buried pipeline under different earthquake action,which shows that the tube corridor structure has obvious damping effect on the internal pipeline,and the construction of the tube Gallery helps to improve the disaster resistance of the urban infrastructure.