内衬混凝土对波纹钢腹板箱梁桥抗弯及抗剪性能的影响

发布时间：2018-11-10 18:14

【摘要】：波纹钢腹板箱梁桥作为一种新型的桥梁结构形式,具有非常明显的优点,可以有效的改善波纹钢腹板箱梁的受力性能。它主要由混凝土顶板、底板、波纹钢腹板和预应力钢索组成。在以往结构抗剪设计中只考虑波纹钢腹板的抗剪性能,而在实际建造的大跨径波纹钢腹板箱梁桥中,零号块墩顶附近一般都会布置内衬混凝土,用以辅助波纹钢腹板进行受力,这样内衬混凝土会影响到波纹钢腹板的受力性能。为了更加明晰这种影响规律,使得对于波纹钢腹板箱梁桥的研究更加完善,进行内衬混凝土对结构抗弯及抗剪力学性能影响规律的研究十分必要。论文查阅和总结了大量国内外研究资料,介绍了波纹钢腹板箱梁桥的发展史及国内外研究现状,阐述了波纹钢腹板箱梁桥弯曲、剪切计算分析理论。论文以某波纹钢腹板组合连续箱梁桥为工程背景,建立不同厚度及长度的内衬混凝土有限元实体模型,通过有限元分析软件对比分析。对其在不同内衬混凝土布置状况下横截面正应变沿梁高分布规律、剪力滞效应、挠度、内衬混凝土承担剪力比值及弹性屈曲极限荷载等进行深入分析研究。结果表明:布置内衬混凝土可使混凝土顶底板截面正应变减小,钢腹板截面正应变增大;内衬混凝土对墩顶负弯矩区段抗弯性能影响较大,对跨中挠度影响非常小;布置内衬混凝土可以使混凝土顶底板剪力滞效应减小;内衬混凝土厚度超过40cm时,截面剪力主要由内衬混凝土承担;内衬混凝土长度不是越长越好;内衬混凝土可以限制钢腹板的横向变形,使钢腹板屈曲前剪应力明显降低;内衬混凝土厚度超过80cm时,钢腹板屈曲极限荷载的减小幅度趋于稳定。
[Abstract]:Corrugated steel web box girder bridge, as a new type of bridge structure, has obvious advantages and can effectively improve the mechanical performance of corrugated steel web box girder. It is mainly composed of concrete roof, floor, corrugated steel web and prestressed steel cable. In the past, the shear resistance of corrugated steel webs was only considered in the structural shear design, but in the actual long-span corrugated steel web box girder bridges, concrete lining was usually arranged near the top of block zero piers to assist the corrugated steel webs to carry out the force. In this way, concrete lining will affect the mechanical performance of corrugated steel web. In order to make the research of corrugated steel web box girder bridge more perfect, it is necessary to study the influence of lining concrete on the flexural and shear mechanical properties of the structure. This paper reviews and summarizes a large number of domestic and international research materials, introduces the development history of corrugated steel web box girder bridge and the present research situation at home and abroad, and expounds the theory of bending and shear analysis of corrugated steel web box girder bridge. Taking a corrugated steel web composite continuous box girder bridge as the engineering background, the finite element solid model of lined concrete with different thickness and length is established in this paper, and the finite element analysis software is used to compare and analyze the model. The distribution law of normal strain along the beam height, shear lag effect, deflection, shear ratio of lining concrete and ultimate load of elastic buckling are deeply analyzed and studied. The results show that the positive strain of concrete roof and bottom slab can be decreased and the positive strain of steel web section will be increased by placing lined concrete, and the influence of lining concrete on the flexural behavior of the negative moment section of pier top is great, and the influence on the deflection of span is very small. When the thickness of lining concrete exceeds 40cm, the cross-section shear force is mainly borne by lining concrete, and the length of lining concrete is not the longer the better. The concrete lining can limit the transverse deformation of the steel web and reduce the shear stress of the steel web before buckling obviously, and when the thickness of the lining concrete exceeds 80cm, the limit load of the steel web buckling tends to be stable.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

【参考文献】