Analysis On Seismic Performanece Of Frame With PSRC Vierendeel Truss Transfer Story Under Vertical And Horizontal Ground Motion

The frame with PSRC vierendeel truss transfer story has advantages of large span,clear force transferring route and relatively small weight.However,there is no specific rules in China's current standard and the study on its seismic performance is still not thorough,which limits its application in practical engineerings especially in high-intensity areas where the vertical ground motion must be considered.Therefore,it is really necessary to study the seismic performance of the frame with PSRC vierendeel truss transfer story.Specific seismic design method is proposed in this paper based on China's current standard and the principle of "strong transfer story".And the nonlinear time-history analysis under vertical and horizontal earthquake is done with frames,which is designed according to the proposed design method.At the same time,the structure response of different vertical ground motion(V/H=0?0.65?1.2)is compared in order to discuss the influence of vertical ground motion on the structural response.Main conclusions obtained from this dissertation are as follows:(1)Firstly,based on the principle of "strong transfer story",design of frame with PSRC vierendeel truss transfer story should meet philosophy of multi-line to resist earthquake: The most important components are lower chord and frame-supporting columns,which should be the last line to resist earthquake;Then come upper chord and frame columns joined with transfer story;Other frame columns and middle web member followed;Finally frame beams upon transfer story are also influential.(2)Secondly,frame structures with PSRC vierendeel truss transfer story designed,which is based on the proposed seismic design method,can avoid global or local failure and have good seismic performance.The maximum value of each floor's story drift in frame with PSRC vierendeel truss transfer story always located in the frame upon transfer story.Energy dissipation of structure mainly originates from plasitc deformation of frame beam-ends which is upon transfer story.It is thus clear that design philosophy of multi-line to resist earthquake has been achieved.(3)Thirdly,it is proven that with the increasing value of vertical ground motion,the value and distribution of each floor's maximum lateral displacement and maximum story drift in frame with PSRC vierendeel truss transfer story change little,while the middle-span deflection of the lower-chord beam and the uneven deflection of lower joints of center web members in the transfer story of the frame with PSRC vierendeel truss transfer story are significantly increase.In addition,the value of vertical ground motion has great impact on the local response.However,these structures can all show great global and local seismic performance,energy dissipation of structure mainly originates from plasitc deformation of frame beam-ends which is upon transfer story.(4)Lastly,it tends to be unsafe while seismic design of frame with PSRC vierendeel truss transfer story is done under the circumstance of vertical ground motion considered by 10% of representative value of gravity load at magnitude 8 earthquake.