Seismic Response Analysis Of Cup Type Transmission Line Tower System On Horizontal Layered Site

Seismic wave field propagation will cause coherent effect and traveling wave effect and the attenuation effect in different categories field.Cup type transmission-line tower system has the c haracteristics of flexible strong,big span and strong nonlinear and has a trend of higher height,s pan larger that makes the earthquake could trigger the structure response mode.It should be consi stent in accordance with the single point,multi-point,unidirectional and multidirectional more m ultipoint input seismic calculation for this kind of space structure clearly put forward by seismic code and multipoint input seismic traveling wave effect should be considered when the requirem ents.So it is particularly important to have a research of cup type transmission-line tower system under seismic response considering site features.Based on the seismic wave propagation theory of horizontal layers,finite element models of site-foundation tower line coupling coupling system were established.Systematic analysis of cup type transmission-line tower system under the condition of considering the seismic wave propag ation characteristics of longitudinal uniform excitation,longitudinal non-uniform excitation or m ultidimensional incentive structure seismic response data was performed.Perfected the seismic r esponse data of aseismic design and have a certain scientific value.The main research work and i nnovation includes the following three aspects:(1)Constructed a three dimensional horizontal stratified equivalent viscoelastic model and a nalyzed different seismic wave communication effect in different categories of sites.Expands the influence of earthquake on ground structure effect analysis of the content by the time history ana lysis in the corresponding field seismic wave propagation characteristics including coherent effec t,traveling wave effect,wave attenuation effect that lay the foundation for detailed research on c up type transmission-line tower system seismic response.(2)The tower modeling of different element type was contrasted and the theoretical of form-finding method of wire was analyzed.On the basis of above,three finite element models includi ng three towers and two-span in different heights and different span were established.It can be ob tained that there exsits stiffness mutation in tower head of cup type transmission line tower syste m by modal analysis and the natural vibration frequency decreases and the coupling effect beco mes more significant with the increasing of tower height and span.And the natural vibration freq uency was performed to obtain the calculation formula combined with the current specification s elf-vibration frequency of transmission tower structure calculation method which is suitable for t he cup type transmission line tower system.(3)Compared the simulated experiment data of structural system under longitudinal unifor m excitation,longitudinal non-uniform and multidimensional incentives under the condition on t he basis of seismic wave excitation consistent with the specification requirements and similar of model from vibration characteristic and the shaking table test results.It can be concluded that stif fness mutation in tower head and tower line coupling characteristics are the weakness of structur al system seismic and it will lead to different degree of adverse effects to structure system of seis mic wave field propagation.