既有钢筋混凝土拱肋承载力测试与分析

对于服役多年的钢筋混凝土桥梁,混凝土开裂、钢筋锈蚀等存在着复杂性和随机性,对其性能影响很大。基于实桥两根服役28年的钢筋混凝土拱肋极限承载能力试验研究,详细阐述了拱肋的荷载位移、荷载应变关系、残余承载力以及失效形势,分析了影响承载力的相关因素,给出了服役多年混凝土的本构关系,分别建立了考虑与未考虑老化与损伤的拱肋极限承载能力的有限元计算模型,并对比分析了理论计算值和实验结果。各项研究表明初始裂缝、钢筋锈蚀和拱轴线的线形对结构的承载能力和失效形势有较大影响。

EXPERIMENT AND ANALYSIS ON THE ULTIMATE STRENGTH OF EXISTING REINFORCED CONCRETE ARCH RIB

The structural performance of existing reinforced concrete (RC) bridge gradually deteriorates due to concrete cracking and reinforcement corrosion. Based on experimental study on two 28-year-old existing reinforced concrete arch ribs, the load-displacement and load-strain relationships, the residual load carrying capacity and the failure pattern are explored. Some factors influencing their ultimate strength are analyzed. The constitutive relationship of aged concrete is presented. Finite element model was developed to analyze the ultimate strength of RC arch rib with the consideration of material aging and structural damage. As a comparison, the undamaged and geometrically perfect arch rib is also analyzed. A comparison between the experimental and FEA results is made. It can be concluded that the initial cracks, the reinforcement corrosion and the variation of the arch axial line shape have great influences on the ultimate strength and failure mode.