Treatment of P-Δ Effects in Displacement-Based Seismic Design for SDOF Systems: Fid-Bau Portal

Treatment of P-Δ Effects in Displacement-Based Seismic Design for SDOF Systems

Wei, Bin / Xu, Yan / Li, Jianzhong

Abstract

The displacement-based seismic-design (DSD) methods, owing to their simplicity and efficiency, have been more and more recognized in structural seismic-research communities during the past few years. However, the dynamic $P - Δ$ effect, as has long been well realized to be a key issue in structure earthquake engineering that could amplify the structure’s seismic responses or even trigger the structure’s instability, is still not well solved practically because of the complicated nonlinear mechanism. Therefore, in aim to achieve a practical and general purpose solution to consider the $P - Δ$ effects in various DSD methods for single-degree-of-freedom (SDOF) systems, first, the existing approaches of considering $P - Δ$ effects in current seismic analysis and design were evaluated by carrying out a large set of nonlinear time-history analyses, and then new design formulas and recommendations on threshold of neglecting $P - Δ$ effects and the allowable design thresholds were promoted on the basis of the statistics data. At last, the proposed procedure was illustrated by a seismic-design example.