A DIRECT DISPLACEMENT-BASED SEISMIC DESIGN METHODOLOGY FOR MULTI-LAYER ASYMMETRIC STRUCTURES

The classic displacement-based seismic design procedure depends on the 2-D structural analysis. But the procedure is inapplicable for multi-layer asymmetric structures for considering the imbalance responses and coupled characteristics of responses in the plane of asymmetric structures subjected to earthquake excitations. Therefore, an improved direct displacement-based seismic design method for multi-layer asymmetric structures is presented for the purpose that the procedure attempts to create structures with a specified limited displacement objective of the weakness places of structures under a specified level of seismic intensity. The implementing procedures of this method are introduced in details, in which the theory of equivalent SDOF system is used for simplifying the analysis, the adjustment coefficient of vertical stiffness of structures is defined to reduce the iterative design. A simple multi-layer asymmetric structure is designed for verifying the procedure. From the analysis of the example, the displacement responses of weakness places of the structure meet the expected limits under the specified level of seismic intensity. It is shown that the procedure developed in this paper may be used as an effective seismic design method for multi-layer asymmetric structures.