【摘要】 对钢筋混凝土桥梁上部结构遭受超高车辆撞击后,梁的抗弯承载力问题开展理论分析与试验研究.从事故现场拆运2片主梁(1片受撞损伤最严重,1片外观基本无损伤),对这2片梁进行非线性有限元分析,分别得到它们的计算极限承载力.按正截面受弯破坏设计试验方案,据理论计算得到的极限承载力估计加载量值、确定分级荷载,逐级加载获得受撞钢筋混凝土梁的受力全过程特性和破坏形式.试验表明,受撞梁的正截面破坏始于破损位置,短期抗弯承载力计算可以只考虑构件受损程度.在现行《公桥规》的基础上,文中通过引入梁的损伤系数,给出受损梁的承载力计算公式及其结果.本文公式和研究分析结果可为受撞钢筋混凝土梁的正截面承载力计算提供依据.更多还原

【Abstract】 Both theoretical analyses and experimental researches are carried out to obtain flexural bearing capacity of the main girders after the superstructure of a reinforced concrete bridge was collided by an ultra-high vehicle.Two girders were dismantled from the accident bridge(one with the most serious collision damage and the other without obvious exterior damage).Their ultimate flexural bearing capacities were respectively calculated by nonlinear finite element method.The experimental scheme was designed according to the bending failure mode of the normal section.Based on the ultimate bearing capacities by theoretical calculation,maximum test load is estimated and the graded load is determined.The test by step-by-step loading reveals the full-process characteristics and failure modes of the collided reinforced concrete beams.The experimental results show that the break of the normal section of the impacted beam begins at the damaged location,and only the damage degree of the components is taken into account while the short-term bending capacity is being calculated.Based on the current Code for Design of Reinforced Concrete and Prestressed Highway Bridges and Culverts(JTG D62-2004),the formulas for the bearing capacity of the damaged beam and its analysis results are presented by introducing the damage coefficient of the collided beams.The formulas and test analysis results can meet the demand of the calculation of the normal section bearing capacity of the collided reinforced concrete beam.更多还原