钢—混叠合梁体外预应力加固施工工艺研究

Research on Construction Technology of External Prestressed Reinforcement of Steel-Concrete Composite Beam

针对大跨径的钢—混叠合梁桥体外预应力加固中,常规齿板存在施工复杂、自重增加量大、工期长、对原结构损伤较大等缺点,以及常规转向块存在施工复杂、与原结构整体性较差等缺点,以某65 m钢—混叠合梁为工程依托,对锚固钢齿板及转向块进行合理优化,对优化后的钢齿板进行局部应力分析。与常规齿板及常规转向块相比,优化后的钢齿板与原结构形成整体,受力性能良好,对原结构损伤小,施工便捷;优化后的转向块利用原结构横隔板,整体性能良好,有利于后期预应力钢绞线的更换;同时,优化后的锚固钢齿板应力满足规范要求。结果表明,优化后的方案技术可行。

During the external prestressing strengthening of large-span steel-concrete composite beam bridges, the conventional tooth plate has the disadvantages of complicated construction, large increase in self-weight, long construction period, and large damage to the original structure;and the conventional steering block is featured with complicated construction, and poor integrity with the original structure. Based on a 65m steel-hybrid composite beam, the anchorage steel toothed plate and steering block are optimized reasonably, and the local stress of the optimized steel toothed plate is analyzed. Compared with the conventional toothed plate and the conventional steering block, the optimized steel toothed plate is integrated with the original structure, which is featured with good mechanical performance, little damage to the original structure and convenient construction, it is advantageous to replace the prestressed steel strand in the later period, and the stress of the optimized anchorage steel toothed plate meets the requirements of the specifications, which shows that the optimized scheme is feasible.