宽幅混凝土斜拉桥箱梁剪力滞效应
发布时间：2018-12-11 08:10
【摘要】：箱型截面梁由于其承受正负弯矩能力强、抗扭刚度大、截面效率指标高、稳定性好等显著优点，被广泛用于桥梁结构中。但又由于其薄壁、宽翼缘的结构特征，导致箱型梁在荷载作用下产生扭转、畸变、翘曲等不同于其它开口截面的受力特征，其中箱型梁翼缘的剪力滞效应问题更是不容忽视。产生剪力滞效应的结果是使箱梁翼缘上产生局部应力集中，如果在桥梁结构的设计和施工过程中忽略这种效应，将会降低结构的安全储备，甚至导致结构的破坏。因此本文结合依托工程，研究宽幅薄壁单箱六室箱型截面预应力混凝土梁斜拉桥的剪力滞效应，具有其实用的工程价值和理论研究意义。本文完成的主要工作有： （1）查阅了国内外大量的参考文献，综述了目前剪力滞效应的研究现状、研究理论与方法，并进行了对比分析，指出各种方法的局限性和适用场合，提出了现有的研究剪力滞理论需要改进的地方。最后说明本论文研究的意义和必要性。 （2）阐述了箱形梁的受力特点、薄壁箱形梁剪力滞后效应的概念。 （3）阐述了斜拉桥基本结构体系及其特点。 （4）用MIDAS/Civil建立了依托工程的有限元模型，分别分析了漂浮体系、半漂浮体系、塔梁固结体系和刚构体系四种斜拉桥结构体系在典型施工阶段和成桥荷载作用下一般截面（无横隔板截面）和特殊截面（有横隔板）的剪力滞效应，并进行了的对比分析。 分析结果表明，宽幅混凝土斜拉桥剪力滞效应较突出，，剪力滞系数沿纵向呈现明显的分区现象。
[Abstract]:Box section beam is widely used in bridge structure because of its strong positive and negative bending moment, large torsional stiffness, high cross-section efficiency index and good stability. However, due to the structural characteristics of thin-walled and wide-flange, the box girder has torsion, distortion and warpage under load, which is different from other open section, and the shear lag effect of box girder flange can not be ignored. The result of shear lag effect is the local stress concentration on the flange of box girder. If this effect is ignored in the design and construction of bridge structure, the safety reserve of the structure will be reduced and even the structure will be destroyed. Therefore, it is of practical engineering value and theoretical significance to study the shear lag effect of prestressed concrete girder cable-stayed bridge with wide thin-walled single box and six-room box section in this paper. The main works of this paper are as follows: (1) A large number of references at home and abroad are reviewed, and the current research status, theories and methods of shear lag effect are summarized, and a comparative analysis is made. The limitations and applications of various methods are pointed out, and the existing research on shear lag theory is put forward. Finally, the significance and necessity of this paper are explained. (2) the stress characteristics of box beam and the concept of shear lag effect of thin wall box beam are expounded. (3) the basic structure system and its characteristics of cable-stayed bridge are expounded. (4) the finite element model of supporting engineering is established by MIDAS/Civil, and the floating system and semi-floating system are analyzed respectively. The shear lag effects of general section (without cross diaphragm section) and special section (with cross diaphragm section) of four cable-stayed bridge systems under typical construction stage and bridge load are analyzed and compared. The results show that the shear lag effect of wide-width concrete cable-stayed bridge is prominent and the shear lag coefficient appears obvious zoning phenomenon along the longitudinal direction.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.27
本文编号：2372204
[Abstract]:Box section beam is widely used in bridge structure because of its strong positive and negative bending moment, large torsional stiffness, high cross-section efficiency index and good stability. However, due to the structural characteristics of thin-walled and wide-flange, the box girder has torsion, distortion and warpage under load, which is different from other open section, and the shear lag effect of box girder flange can not be ignored. The result of shear lag effect is the local stress concentration on the flange of box girder. If this effect is ignored in the design and construction of bridge structure, the safety reserve of the structure will be reduced and even the structure will be destroyed. Therefore, it is of practical engineering value and theoretical significance to study the shear lag effect of prestressed concrete girder cable-stayed bridge with wide thin-walled single box and six-room box section in this paper. The main works of this paper are as follows: (1) A large number of references at home and abroad are reviewed, and the current research status, theories and methods of shear lag effect are summarized, and a comparative analysis is made. The limitations and applications of various methods are pointed out, and the existing research on shear lag theory is put forward. Finally, the significance and necessity of this paper are explained. (2) the stress characteristics of box beam and the concept of shear lag effect of thin wall box beam are expounded. (3) the basic structure system and its characteristics of cable-stayed bridge are expounded. (4) the finite element model of supporting engineering is established by MIDAS/Civil, and the floating system and semi-floating system are analyzed respectively. The shear lag effects of general section (without cross diaphragm section) and special section (with cross diaphragm section) of four cable-stayed bridge systems under typical construction stage and bridge load are analyzed and compared. The results show that the shear lag effect of wide-width concrete cable-stayed bridge is prominent and the shear lag coefficient appears obvious zoning phenomenon along the longitudinal direction.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.27
【参考文献】
相关期刊论文 前3条
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3 罗旗帜;薄壁箱形梁剪力滞计算的梁段有限元法[J];湖南大学学报;1991年02期
本文编号：2372204
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