Improved direct displacement-based seismic design procedure

The traditionary direct displacement-based seismic design depends on supposing the elastic mode and corresponding lateral force distribution of structure,in which the supposition is liable to cause some deviations.So,an improved direct displacement-based seismic design procedure for structures is presented.In the procedure,by means of conceptual design,the modes and corresponding equivalent SDOF systems are obtained,and the lateral equivalent stiffness of structure can be designed on the basis of the displacement objective and the equivalent SDOF system.Finally,the structural stiffness is adjusted to make the weak places of the structure meet the limited displacement objective under the specified level of seismic intensity.The implementing procedures of this method are introduced in details,in which the adjustment coefficient is defined to reduce the iterative design.With the analysis of an example,it is shown that the procedure developed in this paper may be used as a simple and effective seismic design method for multi-storey structures.