荷载重分布对退化钢筋混凝土桥可靠性的影响

为了能依据体系可靠度的概念对桥梁进行优化设计 ,找到体系可靠度与失效构件数目及失效顺序的关系 ,笔者以某钢筋混凝土简支梁桥为例 ,将 5片T梁看作一个主梁体系 ,针对几种不同的主梁体系失效模式 ,采用“修正刚性横梁法”计算了当主梁体系中有一片或两片梁失效后剩余各主梁的荷载横向分布系数 ,讨论了荷载重分布对单片主梁和主梁体系可靠性的影响。结果表明 :失效梁离剩余梁越近 ,失效梁越多 ,剩余梁可靠性越低 ,而随着荷载重分布程度的加深 ,体系可靠度有所增加。

Effect of Load Redistribution on the Reliability of Deteriorating Reinforced Concrete Bridge

In order to make an optimum design for the bridge according to the concept of system reliability, and find the correlation between the system reliability and failure beams' number and failure sequence, five T beams of a simple reinforced concrete bridge are taken as a beam system. According to failure modes of several different systems, the load transverse distribution factors of remained beams are calculated by modified rigidity crossbeam method after one or two pieces of beams in beam system failed. The effect of load redistribution on the reliability of single beam and beams system is analyzed. The result indicates that the nearer with the failure beams is, the lower reliability of remained beams will be, however, the system reliability will increase with the load redistribution deepening.