Analysis on the torsion parameters of L-shaped high-rise isolation buildings

The dynamic behaviour of an irregular L-shaped high-rise base-isolation structure under different direction seismic waves has been analyzed. Then the most unfavorable displacement ratio variation between the non-isolation design and the isolation story design is studied with continuous optimizing eccentricity. The motion equation of a high-rise baseisolated structure is established and its eccentricity solving process is discussed, and based on the above theoretical calculations of the structural eccentricity and displacement ratio, 5 examples are analyzed with ETABS. The results show that the effect of the eccentricity changes on the torsion of irregular L-shaped high-rise structure is similar with the general structure,they all have the simlar law.The isolation design can effectively improve the serious torsional problem in the irregular L-shaped structure. In the meantime, the structural displacement ratio decreases with the reduction of the spacing distamce between the stiffness centre of isotation layer and the mass centre of superstructure. So its necessary to reduce the eccentricity under the condition of meeting isolation design requirements so as to make sure of damping effect and structural safety during the isolation design of irregular structures.