改进型简支装配式小箱梁设计及整体模型横向活载效应分析
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摘要
以上海市大芦线为工程背景,介绍了改进型简支装配式小箱梁的构造特点,建立实体有限元模型,分析研究组合式小箱梁各片梁在不同偏载工况下的内力横向分布,量化对比横隔板对平衡弯矩横向不均匀分配的影响,得出了对于跨径22 m桥宽较窄的情况下,设置跨中横隔板对横向整体受力影响较小的结论。通过实体计算分析小箱梁整体模型在活载作用下的横向弯矩效应,得出了桥面板横向受弯以局部荷载效应为主,整体效应为次;集中荷载作用下的局部荷载效应明显,尤其是沿计算跨度方向的局部效应更为突出的结论。比较杆系模型与实体模型计算桥面板横向弯矩的误差,得出杆系模型结果偏于安全的结论。
Based on engineering project of Dalu Line in Shanghai,the design of improved fabricated small box girder bridge was introduced.Load transverse distribution of different unbalance load cases were studied by the method of finite element analysis.Quantitative comparisons of the influence the transverse moment distribution due to diaphragm were made,the result shows that diaphragm contributes little to the transverse distribution for narrow bridge with the span under 22 m.Furthermore,analysis of transverse moment effect under whole-scale model was carried out,which came out with the conclusion that partial effect plays more important role than overall effect in transverse bending of bridge deck.Partial effect is obvious under concentrated force, especially in the direction along the effective span.Comparison of the deviation between calculation results of beam model and finite element model are presented,which indicated that beam model is conservative for bridge design.
Based on engineering project of Dalu Line in Shanghai,the design of improved fabricated small box girder bridge was introduced.Load transverse distribution of different unbalance load cases were studied by the method of finite element analysis.Quantitative comparisons of the influence the transverse moment distribution due to diaphragm were made,the result shows that diaphragm contributes little to the transverse distribution for narrow bridge with the span under 22 m.Furthermore,analysis of transverse moment effect under whole-scale model was carried out,which came out with the conclusion that partial effect plays more important role than overall effect in transverse bending of bridge deck.Partial effect is obvious under concentrated force, especially in the direction along the effective span.Comparison of the deviation between calculation results of beam model and finite element model are presented,which indicated that beam model is conservative for bridge design.
引文
[1]李健.小箱梁结构在高等级公路中的应用发展及运营病害综述[J].公路交通科技,2015(4):9-12.
[2]刘效尧徐岳.梁桥[M].北京:人民交通出版社,2011.
[3]公路钢筋混凝土及预应力混凝土桥涵设计规范:JTG D62-2004[S].2004.
[4]公路桥涵设计通用规范:JTG D60-2004[S].2004.
[2]刘效尧徐岳.梁桥[M].北京:人民交通出版社,2011.
[3]公路钢筋混凝土及预应力混凝土桥涵设计规范:JTG D62-2004[S].2004.
[4]公路桥涵设计通用规范:JTG D60-2004[S].2004.