Analysis on seismic superstrength capacity of lateral force resistance structure of Guangzhou West Tower
This paper analyzes the main reasons for the minor damage to the Guangzhou West Tower model structure after encountering a rare earthquake of intensity nine in the shaking table test.The overstrength capacity of the lateral force-resisting system of the West Tower structure was studied.The safety and reliability of the seismic design spectrum in the DBJ/T 15-92-2021'Technical specification for concrete structures of tall building'in Guangdong Province(referred to as Provincial standard)were verified.Using the GuangZhou West Tower Prototype structure(referred to as"GZTP structure")and the corresponding redesigned structure based on the Provincial standard(referred to as"NGZT structure"),the response spectrum analysis and the elastoplastic dynamic time history analysis were carried out.The differences between the story shear force and overturning moment calculated based on the seismic design spectrum in the GB 50011-2010'Code for seismic design of buildings'and that in the provincial standard were discussed,with their reasons explained and the corresponding overstrength coefficients of the lateral force-resisting systems determined.The results show that the GZTP structure with the lateral force-resisting system designed by wind-load control has a seismic capacity of"not damage encountering rare intensity earthquake".The overstrength coefficient of GZTP structure is 7.6 based on overturning moment.The yielding overturning moment at structural base,determined by the elastoplastic incremental dynamic time history analysis,exceeds the elastic seismic demand for a rare earthquake of intensity eight.This explains that the GZTP structure with the seismic fortification demand of intensity seven had little stiffness degradation without apparent damage after encountering a rare earthquake of intensity nine in the shaking table test.Moreover,the overstrength coefficient of NGZT structure is 10.3 based on overturning moment.
Guangzhou West Towerlateral force-resisting structureseismic spectrumtime history analysisoverstrength capacity