实现整孔架设的48 m UHPC简支箱梁设计
The implementation of design for integrally erected 48 m UHPC simple-supported box girder

提出一种设密集横隔板的整孔预制架设48 m UHPC简支箱梁桥新方案。该方案将超高性能混凝土(UHPC)、密集横隔板薄壁箱梁和预应力钢束有机结合,不仅提升了预制架设简支箱梁的跨径,而且消除了传统大跨径简支PC梁桥的抗裂性差、残余徐变变形难控制的问题。通过对跨径48 m UHPC简支箱梁试设计和分析,结果表明:该方案箱梁各板件厚度大幅减小,箱梁吊装重量与32 m跨常规PC箱梁相当,具有良好的经济性;主要计算结果均能满足规范要求;密集横隔板有效降低了箱梁的横向应力、扭转变形以及截面畸变。整孔预制架设48 m UHPC简支箱梁桥是一种在安全、经济、耐久各方面具有竞争力的梁桥新方案。
A novel integrally prefabricated and erected 48 m ultra-high-performance concrete (UHPC) simple-supported box girder bridge with dense diaphragm plate was proposed.By combining UHPC,thin-walled box girder with dense diaphragm plates and external prestressing into the novel box-girder scheme, not only can the span length of prefabricated and erected simple-supported box girder bridges be improved,but also the ever existing problems in long-span simple-supported PC bridges,such as the cracking in concrete girders and the excessive residual creep deflection at midspan,may be eliminated.A trial-design and analysis for a simple-supported box girder bridge built from UHPC with span length of 48 m is presented,and the results show that the thicknesses of its components can be decreased greatly,the self-weight of superstructure may be equivalent to that of a 32 m PC simple-supported box girder,a good economy may be achieved. And all of the main calculation results comfort code requirements. Besides, the transverse stress,the torsional deformation and the cross section deformation decreased effectively by using the dense diaphragm plates