箱梁合龙段底板崩裂机理及设计

发布时间：2019-01-18 20:18

【摘要】：基于非线性有限元数值模拟方法,考虑混凝土非线性力学特性,建立了包含竖向双层波纹管孔道的精细化数值有限元模型,分析了箱梁合龙段底板从开始加载至最终破坏的损伤发展过程.基于精细化数值模型分析结果,讨论了崩裂成因.研究表明,箱梁合龙段底板崩裂成因共有5种:孔肋间混凝土竖向受拉、波纹孔道下方混凝土冲切、孔肋顶部和底部混凝土横向开裂、波纹管与混凝土的剥离以及底板弯曲开裂和梗腋位置剪切开裂.根据5种崩裂成因出现的先后顺序,认为控制底板崩裂破坏形式为波纹管下方混凝土冲切破坏及孔肋间竖向受拉破坏.最后,提出了孔肋间受拉破坏承载能力设计公式和底板抗冲切承载能力设计公式.
[Abstract]:Based on the nonlinear finite element numerical simulation method and considering the nonlinear mechanical properties of concrete, a refined numerical finite element model including vertical double-layer bellows is established. The damage development process of the bottom plate of the closure section of box girder from the beginning to the final failure is analyzed. Based on the results of refined numerical model, the causes of disintegration are discussed. The results show that there are five kinds of causes of the crack in the bottom slab of the closure section of box girder: vertical tension of concrete between holes, punching of concrete under corrugated channel, transverse cracking of concrete at the top and bottom of the hole rib, Corrugated pipe and concrete peeling, bottom bending cracking and stem axillary shear cracking. According to the sequence of formation of five kinds of cracks, it is considered that the failure forms of controlling the cracking of bottom slab are the failure of punching shear of concrete under bellows and the vertical tensile failure between holes and ribs. Finally, the design formula of bearing capacity of tensile failure between holes and ribs and the design formula of bearing capacity of punching shear of bottom plate are presented.
【作者单位】：山东大学岩土与结构工程研究中心;东南大学交通学院;
【基金】：国家自然科学基金青年基金资助项目(51108152,51108249)
【分类号】：U441

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