Frame Structure Response Analysis Of Near-fault Earthquake

In recent years,earthquakes have occurred frequently,from the Chi-chi earthquake,the Hanshin earthquake,the Beiling earthquake to the 2008 Wenchuan earthquake in China.Due to the special effects of near-fault earthquakes,it will cause great damage to the engineering building structure.Most of the property damage and casualties in the earthquake were concentrated in the near fault area.Therefore,it is necessary to analyze the mechanism and failure mode of the frame structure under the action of near-fault earthquakes,and lay a foundation for constructing the seismic design and corresponding earthquake prevention and mitigation measures of this type of structure near the near fault area.Comparing the near-fault seismic response of the frame structure with the near-fault with or without velocity pulse seismic wave not only has theoretical significance,but also provides a reference for seismic design of building engineering.This paper establishes an analytical model for the three-span reinforced concrete plane frame structure in the depth direction of the four-story office building.Four sets of seismic records numbered RSN879,RSN764,RSN1148 and RSN4097 in the PEER database were selected as seismic inputs to the established analytical model.The four-layer three-span reinforced concrete plane frame structure under the near-fault earthquake with or without velocity pulse is compared.The relative lateral displacement of each column,its average value,the bottom shear force of each column of the first layer and the Mises cloud diagram of shear force and displacement are calculated.The research results are as follows:after comparing the seismic wave divisions of RSN879,RSN764,RSN1148 and RSN4097,the influence of the relative interlayer displacement of each layer of the building is known.As a whole,any group of seismic waves have the state of presence and absence of velocity pulses.The effect of the velocity pulse on the structure caused by the seismic wave is significantly larger than that of the velocity-free pulse;in the same state of the same seismic wave,the interlayer displacement of each layer decreases from low to high compared with the no-velocity pulse.The relative lateral shift of each column of the structure under the action of velocity pulse is larger:the next to fourth layers of the RSN879 seismic wave increase respectively.For the established three-span,four-story reinforced concrete plane frame structure model,under the seismic records of RSN879,RSN764,RSN 1148 and RSN4097,compared with the velocity-free pulsed earthquake,the first column of the structure under the action of velocity pulse earthquake the shear strength at the bottom of the column is significantly increased.Compared with the no-pulse seismic wave action,the seismic response of the structure with velocity pulsed seismic waves is significant.