Earthquake Resistance Behavior Of Frame-core Wall Structure Subjected To Vertical Ground Motion

The traditional viewpoint of earthquake engineering thinks that horizontalearthquake action plays the most important role in structure failure and verticalearthquake action is insignificant. But, in the later time, a large number of seismicrecords show that vertical ground motion relatively obvious. A great deal of evidencesfrom the earthquake disaster is hard to be interpreted with traditional view. However,this can be explained properly by the influences of vertical earthquake force. There aremany scholars begin to question on traditional view. So, the influence of earthquakeaction in vertical directions on frame-core structure needs further research.Building structure model uses PERFORM-3D software. First, this article makesseismic response analysis to model using response spectrum analysis under twoconditions. Condition1is that the one-dimensional earthquake action contrast withone-dimensional and vertical earthquake action. Condition2is that bidirectionalhorizontal earthquake action contrast with bidirectional and vertical earthquake actioninput simultaneously. The ratio of bidirectional horizontal earthquake ground responsespectra is1:0.85which is recommended by Chinese code. Three-dimensionalearthquake ground response spectra ratio adopts1:0.85:0.65.Results show that verticalseismic action has no effect on horizontal displacement of the structure. However,vertical seismic action has significant influence on vertical displacement of frame, axialforce of frame column, mid-span moment of frame beam and moment at beam end.Axial force of shear wall increases little.In order to further research into the vertical seismic action, this article has carriedon the elastic-plastic seismic response analysis of structure. Analysing seismic response of the structure under two conditions. The typical earthquake records are EL centro,TAFT, and TianJin. The results are similar to response spectrum method. The tophorizontal displacement time-history curve is close under two-dimensional andthree-dimensional seismic inputs. The inter-story drift is basically corresponds undertwo conditions. Vertical seismic action has little impact on structural horizontaldisplacement. Axial force of frame column and shear wall varies obviously. Axial forceof frame column increases maximumly66.1%and bear tension stress. The status ofcomponent becomes tension bending and tension shear from compression bending andcompression-shear. The component bearing capacity is reduced obviously and structuralseismic resistance should be also considered in this case. Mid-span moment andmoment at beam end varies severely under vertical seismic action and is larger thansituation with no vertical earthquake. Vertical seismic accelerate the deformationdevelopment of frame beam. The displacement increment at mid-span increaseobviously.The results show that vertical seismic action can’t ignore and the code provisionsto vertical seismic action need further research. Researching on the effects of verticalground motion for structure seismic resistance needs more comprehensive and deeply.