摘要
以北京市门头沟地区新建的一座简支梁桥和一座连续梁桥为例,将实测数据、理论分析和有限元模拟相结合研究了环境温度和边界条件对混凝土梁式桥自振频率的影响。分别对两座桥梁进行了24 h的实时监测,每隔一小时采集环境温度、自振频率、伸缩缝宽度等数据。从理论上分别分析了简支梁和连续梁自振频率的影响因素。针对分析结果,用有限元模拟了温度影响下橡胶支座刚度变化、伸缩缝不能正常伸缩和混凝土弹性模量随温度变化这三种情况下桥梁的工作状态,并与实测结果进行对比。结果表明,自然状态下橡胶支座刚度的变化对混凝土梁式桥的自振频率几乎没有影响。混凝土弹性模量的变化、伸缩缝的工作状态都会影响桥梁的自振频率,但对不同结构形式的桥梁影响权重不同。
Take a newly built simple supported beam and a continuous beam in Mentougou as examples, experimental data, theoretical analysis, and finite element simulation were combined to study the effect of environmental temperature and boundary conditions on natural frequencies of concrete beam bridges. First of all, 24 hours' monitor was performed and experimental data including environmental temperature, natural frequencies, and the width of expansion joints were recorded every one hour. Then influences on natural frequencies of simple supported beams and continuous beams were discussed in theory, respectively. Finally, according to the results of theoretical analysis, finite element models of the two bridges were built by Midas Civil to simulate three working conditions of the bridges: the change of stiffness of rubber bearings, expansion joints' failure, and the change of elastic modulus. The results suggest: under natural conditions, the change of stiffness of rubber bearings almost has no effect on natural frequencies of concrete beam bridges. Both the change of elastic modulus and the working condition of expansion joints can influence the natural frequencies of concrete beam bridges but the weights are different. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第8期164-172,共9页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(51278031)
关键词
自振频率
环境温度
边界条件
橡胶支座
伸缩缝
Bearings (structural)
Boundary conditions
Concrete beams and girders
Concretes
Elastic moduli
Expansion
Expansion joints
Natural frequencies
Nonmetallic bearings
Rubber
Stiffness
