Abstract
The authors have worked out an earthquake response analysis program for use in a space frame vibration, with the flexural rigidity of earthquake-resistant walls and floor slabs taken into consideration, so as to evaluate the uplift of isolators and the earthquake response characteristics of base isolated high-rise buildings. This earthquake response analysis program for the space frame vibration makes it possible to simultaneously input three components of earthquake motion-two components of horizontal motion plus one component of vertical motion. Compared with ordinary analysis instruments, the program serves to grasp in fuller detail the uplift of isolators and the earthquake response of superstructure of base isolated high-rise building. It is confirmed, with the help of this program, that when the strong motion inputs into the high aspect ratio base isolated high-rise building, the tension region of corner isolator of base isolated high-rise building records a tension bearing as high as σ_t=2N/mm^2, so that the compressive response quantity exceeds a maximum allowable compressed strength, with the isolator placed in a buckling condition. As the aspect ratio rises higher, the fluctuation axial force will have larger effects, further building up the compressive stress. With the fluctuation axial force having a larger compressive stress at the corner than elsewhere, the compressive stress of the corner isolator produces a high compressive stress.
