| According to the fault slip direction and the difference of ground motion propagation mechanism,the near-fault pulse-type ground motion can be divided into near-fault forward directional impulse ground motion and near-slip slip-type pulse ground motion.These two types of pulse-type ground motion exhibit different pulse characteristics and long-period characteristics due to the difference in the form of their velocity pulses.In this paper,the energy-based velocity pulse identification method is used to select 10 forward-pulsed ground motions and slip-pulse ground motions from the Taiwanese collection seismic database,and the velocity pulses in the pulse-type ground motion are extracted to obtain the rejection velocity pulse.The residual ground motion is adjusted to the same intensity level of the pulsed ground motion and the residual ground motion.The acceleration response spectrum and velocity response spectrum of the residual ground motion of the two types of pulsed ground motion and the rejection velocity pulse are compared.Displacement response spectrum;based on HHT transform,the energy characteristics of two types of pulsed ground motions are studied.Then,the two types of pulse-type ground motion and the residual ground motion of the culling speed pulse are input into the multi-layer,middle layer and high-rise base isolation structures respectively.The two types of pulse-type earthquake action are studied under different heights.Use the difference in dynamic response.Based on wavelet transform,two types of pulse-type ground motions are decomposed into wavelet components with different frequency components.From the perspective of frequency,the reasons for the influence of two types of near-fault pulse-type ground motion on different height base isolation structures are explained.Comprehensive thefull text,you can get the following conclusions:(1)The acceleration,velocity and displacement response spectra of the two types of pulse-type ground motions are larger than the residual ground motion of the cull pulse component.The difference between the forward directional pulse ground motion and the residual ground motion response spectrum of the culling velocity pulse is overall.It shows a tendency to increase with the increase of the period,and the difference between the slip-type pulse ground motion and the residual ground motion response spectrum of the culling speed pulse shows a trend of increasing first and then decreasing.(2)The value of the forward directional pulse ground motion is larger than that of the slip-type pulse ground motion,indicating that the long-period characteristic of the forward directional pulse ground motion is more significant than that of the slip-type pulse ground motion;the slip-type pulse ground motion The average value of the energy peak coefficient is smaller than that of the forward directional pulse ground motion,indicating that the energy distribution of the slip-type pulse ground motion is more concentrated throughout the time domain,and the pulse characteristics are more obvious.(3)The top layer displacement,the base shear force and the interlayer displacement angle of the multi-layer,middle layer and high-rise base isolation structures under the action of two types of pulse-type ground motion are larger than the residual ground motion of the rejection velocity pulse,indicating that in two types of pulse-type ground motions The velocity pulse component can increase the dynamic response of the base isolation structure;the velocity pulse component in the slip-type pulse ground motion has a higher influence on the multi-layer and the middle-base seismic isolation structure than the forward-precision pulse ground motion.The opposite is true in the high-rise structure.(4)When the number of layers of the base isolation structure is small,the basic frequency of the structure is large,and the displacement of the structural floor is mainly controlled by the wavelet components of the two bands [0.2-0.39] Hz and [0.39-0.78]Hz,and represents the slip-type pulse earthquake.The moving TCU102-EW has a peak acceleration in the two bands [0.2-0.39] Hz and [0.39-0.78] Hz greater than the TCU103-EW representing the forward directional pulse ground motion,which results ina slip-type pulse ground motion.The effect on the multi-layer and mid-base seismic isolation structure is higher than that of the forward-direction pulse ground motion.(5)When the number of base isolation structures is large,the basic frequency of the structure is correspondingly reduced,and the structural floor displacement is mainly controlled by the wavelet component of the frequency band [0.1-0.2] Hz,while the TCU103-EW representing the forward directional pulse ground motion is The peak acceleration in the [0.1-0.2]Hz band is much larger than the TCU102-EW representing the slip-type pulse ground motion,which causes the forward directional impulse ground motion to have a higher impact on the high-rise base isolation structure than the slip Type pulse ground motion. |
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