Analysis of shock absorption performance of a new staggered story isolation structure under far-field long-period ground motions

Abstract

The new staggered story isolation (NSSI) is a new type of isolation method developed based on base isolation (BI) and mid-story isolation (MSI). Different from ordinary ground motions, far-field long-period ground motions have the characteristics of long period, long duration, and rich low-frequency components, which will have adverse effects on structures with relatively large periods of isolation, which need to be discussed in depth. Based on this, this paper establishes a 16-story frame core tube structure, under rare earthquakes, adopts NSSI, and inputs 7 ordinary ground motions (OGM), 7 far-field anharmonic-like ground motions (FAGM), and 7 far-field harmonic-like ground motions (FHGM), the latter two are collectively referred to as far-field long-period ground motions (FLGM). The seismic response results are obtained through simulation, and the shock absorption performance is compared with non-isolated, BI, and MSI. Combined isolation is proposed, and its displacement-limiting effect under FLGM is discussed. The results show that the seismic responses of various structures under FLGM are much larger than those of OGM; the NSSI structure has better overall shock absorption performance and better safety performance under FLGM; The Combined isolation has a good displacement limiting effect under various ground motions, especially for FHGM, the displacement limiting effect is the best.