钢筋混凝土叠合梁受弯承载力可靠度分析

Reliability analysis on flexure capacity of reinforced concrete composite beam

为了研究钢筋混凝土叠合梁受弯承载力可靠度变化规律,提出基于JC法(当量正态化法)的可靠度分析方法。考虑两阶段荷载比值k(第一阶段荷载与第二阶段荷载的比值)和荷载效应比n(可变荷载效应与恒荷载效应的比值)的影响,应用计算软件MATLAB进行数值分析。结果表明:k对叠合梁的可靠度影响很大,当k接近1.0时,叠合梁的可靠度最大;当k增大或减小时,叠合梁抗弯的可靠度均较低;随着n的增大,可靠度降低。当考虑k和n两个因素对受弯承载力可靠度的影响时,随着k的变大叠合梁受弯可靠度先增大后减小,在1.0附近可靠度达到最大值;与单独考虑荷载效应比n不同,此时随着荷载效应比n的增大,可靠度降低。

In order to study the reliability of flexure capacity of reinforced concrete composite beams,a reliability analysis method based on JC method（ equivalent normalized method） is proposed. k（ the load ratio of the first stage to the second stage） and n（ the ratio of live load effect to dead load effect） are considered to perform the numerical analysis with the computational software MATLAB. Results show that k has a great influence on the reliability of composite beam. When k is close to 1. 0,the reliability of bending of composite beam is the largest. But when k is larger or smaller,the reliability of bending of composite beam is lower. With the increase of n,the reliability decreases. When considering the effect of both k and n on the flexure capacity reliability,the authors find that the bending reliability of composite beam first increases,then decreases with the increase of k. When k is near 1. 0,the reliability also reaches the maximum. The reliability is higherwith the increase of load effect ratio n.