Seismic Wave Passage Effect Analysis Of Frame Structure

There are many researches on seismic response of large span frame structures considering wave passage effect at home and abroad,however,the researches on the short span frame structure considering wave passage effect are very few.It is not only very valuable in theory to study seismic response of the short span frame structure by wave passage excitation,but also has engineering application value for seismic design of structures.Firstly,in this paper,the 10 seismic waves are selected in the PEER seismic database in site classIII.The wave velocity is between 150m/s-250m/s,and the peak acceleration is adjusted according to a proportion "The Regulations of Seismic Design of Building"(GB50011-2010);Midas/Gen finite element software is used to establish three-span,eight-storey framework model,and to analyze uniform excitation and wave passage excitation seismic response in the direction of width and depth,of which is three-span eight-storey frame structure in the action of eight seismic waves in site class?.The column shear force of frame structures under the action of uniform excitation and wave passage excitation are compared,and time history curves of the shear force of the bottom columns facing the seismic wave direction are output;wave passage effect of the three-span eight-storey reinforced concrete frame structure is analyzed by El-Centro and Taft waves downloaded in the PPER database,the commonly used peak acceleration 341.7 cm/s2 El-Centro seismic wave and peak acceleration 152.7 cm/s2 Taft seismic wave in the direction of width and depth.Results show that:when analyzing in the direction of width and depth,compared with uniform excitation,column shear forces of three-span eight-storey frame structure increased under wave passage excitation action,especially in the direction facing the seismic wave.Comparing uniform excitation and wave passage excitation,the author finds that the amount of columns whose column shear forces increases are greater than the amount of columns whose column shear forces decreases.Regarding to analyzing width direction,shear force of the bottom column increases multiples from 0.66 times to 1.70 times in the direction facing the seismic wave.With Regard to analyzing depth direction,shear force of the bottom column increases from 5.22%to 58.62%in the direction facing the seismic wave.When applying the effect of seismic wave in the width direction,wave passage effect is more obvious than in depth direction;When using EL-Centro and Taft waves to analyze wave passage effect,the seismic wave in PPER database is more reasonable to be adopted.Then the Fourier amplitude spectrum of four seismic waves in site class III are obtained by FFT method,using Midas/Gen finite element software to establish three-span,four-storey,five-storey,six-storey,seven-storey,and eight-storey framework model.The author studies on five different frame structures in the direction of width and depth comparing shear force of the bottom column facing the seismic wave direction changes under wave passage excitation and uniform excitation;The author analyzes relation between fundamental frequency of the frame structure with obvious wave passage effect and peak of Fourier amplitude spectrum of the seismic wave.Results show that:when analyzing in the direction of width and depth,the fundamental frequency of the frame structure with relatively obvious wave passage effect is not in the peak area of the seismic amplitude spectrum;The fundamental frequency of the frame structure with not relatively obvious wave passage effect is consistent in the peak area of the seismic amplitude spectrum;when the frequency of the seismic wave in the peak area is equal to or closed to the fundamental frequency of the frame structure,The frame structure shear force of the bottom column increase obviously under the uniform excitation and wave passage excitation.