预制小箱梁中隐盖梁设计关键技术研究

Study on Key Technical Technique of Hidden Bent Cap in Precast Small Box Girder

城市高架桥在地面道路净空和桥面控制标高受限时,隐盖梁门式墩小箱梁能有效降低结构高度,是一种较经济的结构形式。结合设计实例,阐述了隐盖梁门式墩的设计关键点及构造措施,在同类工程中具有借鉴意义。通过对Midas Civil梁单元模型和Midas FEA全桥实体单元模型进行对比分析,可得到以下结论:①在设计中可采用Midas Civil简化模型进行受力分析,且结果偏安全;②在荷载作用下小箱梁与隐盖梁交接处拉应力不大,可不设置预应力筋。

When urban viaduct is restricted by the clearance of the ground road and the control elevation of the bridge deck,the small box girder of the gated pier with hidden bent cap can effectively reduce the structural height,which is a more economical structural form.Combined with a design example,the design essentials and construction measures of hidden bent cap gate pier are expounded,which has the reference significance in similar projects.Through the comparative analysis of the Midas Civil beam element model and the Midas FEA full-bridge solid element model,the following conclusions can be obtained that(1)the Midas Civil simplified model can be used for the stress analysis in the design,and the results are safe.(2)Under the load effect,the tensile stress at the junction of the small box beam and the hidden bent cap is not large,and the prestressed bars may not be provided.