铁路狭窄π形梁设计优化与制造技术研究

Design Optimization and Manufacturing Technology of Railway NarrowΠ-Shaped Beam

结合丰台站改扩建工程,针对狭窄π形梁开展设计优化和制造技术研究。基于混凝土桥梁制造工艺技术,提出桥面宽1.4 m的狭窄π形梁结构优化设计方案,并研究制定狭窄π形梁分体制造的工艺技术。分别建立狭窄π形梁整体预制和分体预制模型,通过理论分析的方法,对比相同设计荷载作用下梁体弹性阶段的竖向位移值和混凝土最大拉应力,结果显示分体预制结构的最大变形较整体预制增大5%,但仍符合规范要求。通过梁体静载试验,观测分体预制再连接的狭窄π形梁体的变形值和混凝土开裂情况,结果均满足规范要求,且有较大安全储备,验证了狭窄π形梁体分体预制工艺的合理性。

Combined with the reconstruction and expansion project of Fengtai Railway Station,the design optimization and manufacturing technology research of narrowπ-shaped beams are carried out.Based on the manufacturing process technology of concrete bridges,the optimal design scheme of the narrowπ-shaped beam structure with a bridge deck width of 1.4 m is proposed,and the process technology for the split manufacturing of the narrowπ-shaped beam is researched and formulated.The results show that the maximum deformation of the split prefabricated structure is 5%larger than that of the whole prefabricated structure,but it still meets the specification requirements.Through the static load test,the deformation value and concrete cracking of the separate precast and reconnected narrowπ-shaped beam are observed.The results meet the requirements of the code and have a large safety reserve,which verifies the rationality of the separate precast process of the narrowπ-shaped beam.