基于梁单元的多室弯箱梁桥空间效应研究
发布时间：2018-10-10 14:31
【摘要】：城市化的发展促使城市交通流量日益增加,设计道路车流量的增加给路线中的桥梁结构设计提出了新的要求。弯梁结构在城市高架桥梁中占有较大比例,是城市桥梁的重要组成部分。弯梁结构的连结作用将彼此分离的各方向道路连为一体。弯箱梁结构较直线箱梁结构受力更为复杂,桥梁计算的空间效应更为明显。弯箱梁结构即使在无偏心荷载作用下,除产生弯矩、剪力效应外,尚且产生一定量值的扭矩。过大的扭矩效应容易在靠近支座的截面突变位置产生斜向裂缝,从而降低结构安全性能。多格室曲线弯梁结构除上述较为突出的扭转效应外,还存在因荷载的偏心加载对箱梁各道腹板的产生较大受力偏差影响的偏载效应。箱梁结构空间传力的复杂性导致最终的应力计算结果与普通直线箱梁结构存在很大不同。基于此本文开展以下研究工作：1、弯梁结构通常在各支点位置设置较为强大的横梁结构。横梁结构的存在使得弯梁结构在扭转荷载作用下变现为约束扭转。约束扭转作用下结构附加产生翘曲双力矩,自由扭矩及约束扭矩。本文对弯梁结构恒活载作用下约束扭转内力效应及应力效应进行计算,并对影响约束扭转效应的结构弯曲半径因素、桥梁格室数量因素进行分析。2、弯梁结构在偏心荷载作用下,其偏载效应较为复杂。通过采用不同的计算方法,定义不同的比值系数,对弯梁结构恒活载的偏心效应进行分析。最后对弯梁结构的弯曲半径、活载加载的偏心距离对偏心效应的影响进行了分析。3、弯梁结构复杂的力学特性使得对结构外加荷载作用下的应力结果难以准确计算。单纯的采用用于普通直梁应力计算的方法对多格室弯梁结构进行计算,所得计算结果往往不能反应结构真实的应力状态。采用空间网格模型能够综合考虑弯梁结构的各项效应,输出的计算结果也更为全面更为精细。
[Abstract]:With the development of urbanization, urban traffic flow is increasing day by day, and the increase of road traffic flow puts forward new requirements for the design of bridge structure in the route. Curved beam structure is an important part of urban bridge because it occupies a large proportion of urban viaducts. The connection of the curved beam structure will be separated from each other in each direction of the road as a whole. The bending box girder structure is more complicated than the straight box girder structure, and the spatial effect of bridge calculation is more obvious. Even if there is no eccentric load, the bending box girder structure produces not only bending moment and shear effect, but also a certain amount of torque. The excessive torque effect is easy to produce oblique cracks near the abrupt position of the section near the support, thus reducing the safety performance of the structure. In addition to the torsional effect mentioned above, there is also a bias load effect due to the eccentric loading on the web of the box girder. Due to the complexity of spatial force transfer of box girder structure, the final stress calculation result is very different from that of ordinary straight box girder structure. Based on this, the following research work is carried out: 1. The bending beam structure usually has strong cross beam structure at each fulcrum. Due to the existence of beam structure, the bending beam structure is turned into constrained torsion under torsional load. Under the constraint torsion, the additional warpage torque, free torque and restrained torque are generated. In this paper, the effect of restrained torsional internal force and stress on the bending beam structure under dead load is calculated, and the factors affecting the bending radius of the structure and the number of the lattices of the bridge are analyzed. 2, the bending beam structure is subjected to eccentric load. The bias effect is complex. The eccentricity effect of dead load of curved beam structure is analyzed by using different calculation methods and defining different ratio coefficients. Finally, the influence of bending radius and eccentricity of live load on eccentricity is analyzed. 3. The method used to calculate the stress of the ordinary straight beam is used to calculate the multi-cell curved beam structure. The calculated results often can not reflect the true stress state of the structure. The effects of bending beam structure can be considered synthetically by using the spatial grid model, and the output results are more comprehensive and precise.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.213
本文编号：2262140
[Abstract]:With the development of urbanization, urban traffic flow is increasing day by day, and the increase of road traffic flow puts forward new requirements for the design of bridge structure in the route. Curved beam structure is an important part of urban bridge because it occupies a large proportion of urban viaducts. The connection of the curved beam structure will be separated from each other in each direction of the road as a whole. The bending box girder structure is more complicated than the straight box girder structure, and the spatial effect of bridge calculation is more obvious. Even if there is no eccentric load, the bending box girder structure produces not only bending moment and shear effect, but also a certain amount of torque. The excessive torque effect is easy to produce oblique cracks near the abrupt position of the section near the support, thus reducing the safety performance of the structure. In addition to the torsional effect mentioned above, there is also a bias load effect due to the eccentric loading on the web of the box girder. Due to the complexity of spatial force transfer of box girder structure, the final stress calculation result is very different from that of ordinary straight box girder structure. Based on this, the following research work is carried out: 1. The bending beam structure usually has strong cross beam structure at each fulcrum. Due to the existence of beam structure, the bending beam structure is turned into constrained torsion under torsional load. Under the constraint torsion, the additional warpage torque, free torque and restrained torque are generated. In this paper, the effect of restrained torsional internal force and stress on the bending beam structure under dead load is calculated, and the factors affecting the bending radius of the structure and the number of the lattices of the bridge are analyzed. 2, the bending beam structure is subjected to eccentric load. The bias effect is complex. The eccentricity effect of dead load of curved beam structure is analyzed by using different calculation methods and defining different ratio coefficients. Finally, the influence of bending radius and eccentricity of live load on eccentricity is analyzed. 3. The method used to calculate the stress of the ordinary straight beam is used to calculate the multi-cell curved beam structure. The calculated results often can not reflect the true stress state of the structure. The effects of bending beam structure can be considered synthetically by using the spatial grid model, and the output results are more comprehensive and precise.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.213
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