Research On Response Of Large-span Structure With Response Spectrum Method Under Non-uniform Seismic Waves Input

For the limited speed of seismic wave and the relatively great distances between the substructure of large-span structure,the seismic waves input into each other is different.The issue of non-uniform seismic waves input is such a complicated process that many factors should be taken into account.The influence of wave passage effect,incoherence effect and local site effect is a significant consideration.Meanwhile considering from the direction aspect of seismic input,it's necessary to think over the effect of multi-component seismic excitations.In this paper,the influence of multi-support and multi-component seismic excitations for response spectrum method is investigated in detail after the formulas considering multi-support and multi-component seismic excitations is derived.In addition to the factors mentioned above,the influences of the response coupling dynamic and static component,different spread directions of seismic waves and different models are considered.The four aspects of work done in this thesis are listed as follows.(1)Based on the acceleration response spectrum suggested in the Code for seismic design of buildings(GB 50011-2010),with the chosen seismic input model of power spectrum,the formulas considering multi-support and multi-component seismic excitations is derived in this paper.The formulas can take the factors of multi-component(including cross directions)seismic excitations,multi-support movements(including the influence of wave passage effect and incoherence effect)and the response coupling dynamic and static component.(2)According to the above work,the derived formulas can be coded into the software program.And the accuracy and the precision of the method can be verified by the program.(3)A symmetrical structure is taken a good use to study the distinguishing feature of the response of pseudo static and dynamic component under single-dimensional excitation at different ground apparent wave velocity.Based on this,the feature of the response of the structure can be shown distinctly.Then the influence of different models,cross directions excitation,the vertical seismic excitation,the response coupling dynamic and static component and incoherence effect is studied.(4)To combine with engineering practice,a complex model is calculated with the response spectrum method under multi-support and multi-component seismic excitations using finite element software and the above program.Compared with the result from time history analysis,the accuracy and the precision of the method can be verified again.Meantime,the influence of different spread directions is taken into account.