A displacement design spectral method adapted to the Chinese seismic design code

Since displacement parameters can describe the seismic performance of structures more scientifically and intuitively, the displacement-based seismic design method has become a research hotspot in the field of Earthquake Engineering. Displacement design spectrum is an essential approach for determining the seismic load in displacement-based seismic design methods. However, the current version of the Chinese seismic design code (after this referred to as the code) does not have relevant provisions on the displacement design spectrum. This paper proposes a displacement design spectrum method adapted to the code based on the characteristics of the actual displacement response spectrum of ground motions to facilitate the practical application. This method does not modify the code parameters but only adds two parameters: control period TDand peak ground displacement PGD, and the added parameters have a one-to-one correspondence with the relevant code parameters. In view of the fact that the force-based seismic design method still plays a dominant role in engineering practice, the proposed displacement design spectrum can be transformed into the acceleration design spectrum. To avoid the contradiction with the code, the proposed acceleration design spectrum is consistent with the code design spectrum when the period is less than 5Tg(site characteristic period). In the long periods, the proposed displacement design spectrum can reflect the main characteristics of the average displacement response spectrum of ground motions, and the proposed acceleration design spectrum is consistent with the average acceleration response spectrum. The research work can serve for the engineering application of the displacement-based seismic design method and guide revising the content about the design spectrum in the code. © 2023 Chinese Vibration Engineering Society. All rights reserved.