Seismic Performance Analysis Of Building Structure With Short-limb Walls

Base-isolated technology has been applied on a large scale in some important buildingssuch as hospital,bank,firehouse, library, and it is being used in many residential structure dueto its remarkable aseismatic performance recently.Meanwhile,structure with special-shapedcolumns and short-limb walls is applied in structure design because of superior function.Thisthesis employes base-isolated technology in structure with special-shaped columns andshort-limb walls,computes horizontal seism reduction coefficient of the structure under thefrequent earthquake, then evaluates the aseismatic performance of the structure under thescarce earthquake by Capacity Spectrum Method and the result is compared with the resultobtained by Time-history method.We can get the conclusion that base-isolated technology canreduce the earthquake action of the structure effectively and ensure the safety of the upperstructure.At last, Capacity Spectrum Method is used in optimization design of the structurewith special-shaped columns and short-limb walls according to the cost-effectiveness criterionto evaluate the performance and economy for this type of structure.Near fault ground motions have the distinct characteristics of hanging wall effect,rupture directivity effect, and velocity pulse-like motion. The present paper examines theinfluence of these motion characteristics on the seismic responses of high-rise buildingstructure with short-pier walls respectively. Near-fault ground motion recordings from thesame earthquake event, i.e. Chi-Chi, Taiwan earthquake (Sep., 21, 1999), are selected as input.The ANSYS software is used to establish a 3D member-shell combined finite element modelfor one high-rise structure with short-pier walls, considering base-isolated and base-fixedanalyse models, the elasto-plastic time history analysis of structure is implemented. Thenumerical results illustrate that the hanging wall and directivity effects amplify the seismicresponses of structural system with short-pier walls remarkably. And the effect of pulse-likeground motions amplify the seismic responses of base-isolated structural much more thanbase-fixed structure. Moreover, the effect of pulse-like ground motions depends highly on thestructural period, and the pulse-like effect on the long-period structure is significant.