【摘要】 当对不确定变量的信息掌握较少时,由概率模型得到的结果是值得怀疑的。本文采用对信息要求少得多的凸集模型描述设计目标位移、水平地震基本加速度和反应谱特征周期的不确定性,结合直接基于位移的设计方法,针对钢筋混凝土桥墩,提出一种界限性能设计方法。该设计方法考虑不确定设计参数的界限范围,得到抗震设计结果的区间,从而可以评定现行抗震规范设计结果的可靠性或抗震设计结果对不确定性设防参数的敏感性。算例结果表明,由我国规范方法得到的设计结果均处于本文基于凸变量分析得到的结果的下半个区间;设计基底剪力对目标位移的变化最敏感,其次为反应谱特征周期,最后为水平地震基本加速度。更多还原

【Abstract】 Results drawn from a probabilistic model are suspectable when inadequate information on uncertain variations are available.In this paper,the convex set model is employed to describe the uncertainties of the design target displacement,horizontal basic acceleration and characteristic period of response spectra,where much less information about these variables is needed.In combination with the direct displacement-based design method,a bound performance-based design method for RC bridge piers is developed.The sections of the anti-seismic design results are obtained by considering the bound of uncertain design parameters so that the reliability of the design results worked out under the current anti-seismic specifications and the sensitivity of the design results to the uncertainty of the anti-seismic parameters can be evaluated.The results of a computational example show that the design by the prevailing anti-seismic specifications falls into the lower bound of the convex set analysis results,and the foundation-base shear force is most sensitive to target displacement,less to the characteristic period of response spectra and the least to the horizontal basic acceleration.更多还原