大跨径简支箱梁现浇施工方案探讨

Discussion on Cast-in-situ Construction Scheme of Long-span Simply Supported Box Girder

以郑万高速铁路ZWZQ-5~ZWZQ-6标段桥梁工程为例,对32 m大跨径简支箱梁施工方案进行探讨。结果表明,充分考虑施工现场环境和技术经济性的情况下,应选用钢管柱+贝雷梁支架现浇法进行简支箱梁浇筑施工,并重点对支架预压进行理论计算和现场试验分析;贝雷梁理论计算最大扰度为49.62 mm,实测最大扰度值为111 mm,贝雷梁、横梁以及钢管立柱的理论最大应力分别为86.5 MPa、 99.65 MPa和59.52 MPa,实测最大应力分别为126.5 MPa、 128.2 MPa和63.2 MPa;贝雷梁受制造加工误差的影响,扰度变形过大,但应力仍处于安全范围内,工字钢横梁可能发生塑性变形,须对其进行加固处理。

Taking the bridge project of ZWZQ 5~ZWZQ 6 bid section of Zhengzhou-Wanzhou High Speed Railway as an example,the construction scheme of 32 m long-span simply supported box girder is discussed.The results show that fully considering the construction site environment and technical economy,the cast-in-situ method of steel pipe column+Bailey beam support is selected for the pouring construction of simply supported box girder,and the theoretical calculation and field test analysis of support preloading are emphasized.The theoretical maximum disturbance of Bailey beam is 49.62 mm,and the measured maximum disturbance value is 111 mm.The theoretical maximum stresses of Bailey beam,beam and steel pipe column are 86.5 MPa,99.65 MPa and 59.52 MPa respectively,and the measured maximum stresses are 126.5 MPa,128.2 MPa and 63.2 MPa respectively.Due to the influence of manufacturing and processing error,the disturbance deformation of Bailey beam is too large,but the stress is still in the safe range,and the I-beam may have plastic deformation,so it needs to be strengthened.