套箍加固拱肋力学性能模型试验研究

摘要

In order to estimate the fundamental mechanical performance and effect of hooping strengthening arch rib,comparative analysis was performed to analyze the crack development regulation,failure process and charac-teristics,bearing capacity and the performance of young-old concrete interface.The test results show that crack distribution regulation,failure process and mode of the two specimens were identical-the deflection difference of failure state was 0.5 mm and the difference of failure load was 2.7%,which means that the structural mechani-cal performance of hooping strengthening arch rib is as same as that of the integrated pouring arch rib.In the loading process,the measuring maximum shear stress of the young-old concrete interface was much smaller than its bearing capacity,and the testing strain of midsection before cracking basically complied with the plane section assumption,which shows that the young-old concrete could work together.Through the analysis of comparative model test,it shows that hooping strengthening technique is reliable and effective for reinforcing arch rib.%为分析套箍加固拱肋的基本力学性能及加固效果，进行套箍加固拱肋和整体浇筑拱肋的对比模型试验，对比分析套箍加固试件的裂缝发展规律、破坏模式与特征、承载能力和新老混凝土结合面的工作性能。试验结果表明：套箍加固模型和整体浇筑模型的裂缝分布规律、破坏过程、破坏模式相同，破坏时挠度相差0．5 mm，破坏荷载相差2．7％，说明二者的力学性能基本相同；试验过程中测试的新老混凝土结合面最大剪应力远小于其承载能力，加载过程中跨中截面测试应变在开裂前符合平截面假定，说明新老混凝土能够作为整体共同受力。通过对比模型试验分析，证明套箍技术加固拱肋是可靠有效的加固方法。