钢筋混凝土桥墩截面能力的概率分析

采用随机模拟方法研究钢筋混凝土桥墩截面的屈服曲率、极限曲率、屈服抗弯能力、极限抗弯能力、曲率延性、塑性转动能力以及抗剪能力的概率特性,得到:屈服曲率、屈服抗弯、极限抗弯和抗剪能力服从正态分布;极限曲率服从极值I型分布;曲率延性、塑性转角服从对数正态分布。分析了桥墩轴力(轴压比)变化对上述截面能力的概率分布及变异性的影响,表明:轴力变化基本上不影响它们的概率分布模型,但对其变异性影响较大;对截面的抗弯能力及截面的屈服曲率,其变异系数随轴力的增加而减小,对截面的极限曲率、曲率延性和塑性转角,其变异系数随轴力的增加而增大。

PROBABILITY CHARACTERISTICS OF CROSS-SECTION CAPABILITY OF RC PIERS

Based on Monte-Carlo simulations, the probability characteristics of cross-section capability of RC pier such as yield curvature, ultimate curvature, yield moment, ultimate moment, curvature ductility, plastic rotation angle and anti-shear capability, are studied. Results show that normal distribution can be used to model yield curvature, yield moment, ultimate moment and anti-shear capability; Gumbel distribution can be used to model ultimate curvature; and lognormal distribution can be used to model curvature ductility and plastic rotation angle. The influences of axial force variations on the probability distributions and the variability of the capability are also analyzed. It is seen that the probability distributions are independent of axial force variations, but dependent upon the variability. For yield curvature, yield moment and ultimate moment, the variation coefficients decrease with the increase of axial force. For ultimate curvature, curvature ductility and plastic rotation angle, the variation coefficients increase with the increase of axial force.