| Popis: |
The multi-mode adaptive displacement-based pushover (MADP) method has recently been developed to use the advantages of two advanced ‘multi-mode’ and ‘adaptive’ pushover analysis (POA) methods and accurately estimate the seismic response of RC buildings. The procedure predicts the seismic response of the frames through several adaptive modal POAs. In MADP method, a POA is conducted for each mode and continued up to a target-displacement, calculated using the nonlinear time-history analysis (NTHA) of the equivalent single-degree-of-freedom system subjected to a set of ground motion records. However, this methodology is time-consuming and needs more computational effort. To overcome this drawback, a simplified MADP procedure (i.e., SMADP) is proposed in this paper, which benefits from a new simplified integration method to analyze the structures under the dynamic loads and estimate the modal target-displacements with less computational effort. Unlike MADP approach, the SMADP procedure can satisfactorily calculate the modal target-displacements without the need for updating them at each analysis step. The SMADP procedure is applied to the analysis of four tall steel frames with 10-, 15-, 20-, and 30-stories, and the seismic demands are obtained for three various seismic risks. The NTHA results are also presented as the benchmark solution. The predictions from the original MADP and two advanced ‘multi-mode’ pushover methods are also provided for comparison. It is demonstrated that the SMADP approach can adequately predict the target-displacement of the structures and almost provide similar predictions of the original MADP method for the example structures with less computational effort. |
