人行激励下大跨度楼板及人行天桥振动舒适度设计

发布时间：2018-07-12 15:27

本文选题：振动舒适度 + 人行激励　；参考：《昆明理工大学》2014年硕士论文

【摘要】：近年来,随着结构向轻质、大跨度、纤柔方向发展,越来越多的工程由于振动舒适度问题导致其难以正常使用,部分建筑进行了重新加固或改造甚至完全拆除。由此可见,一旦建筑结构出现了振动舒适度问题,解决的难度和代价将会很大,因此对建筑结构的振动舒适度进行研究是必不可少的。本文结合结构动力学、人机工程学和概率论对人行激励下楼板和人行天桥的振动问题进行了系统研究。首先,本文介绍了有关楼板和人行天桥振动舒适度的设计标准和评价方法。然后通过由均匀试验设计法确定的30条人行荷载根据Ellingwood方法构造激励函数,结合newmark算法对单人作用下的楼板结构和人行天桥分别进行了大量的计算。给出了楼板结构在单人移动荷载下的竖向最大加速度响应谱和均方根加速度响应谱,人行天桥在人-桥相互作用下的侧向最大加速度响应谱和均方根加速度响应谱。分析了响应谱对结构的跨度、边界条件、阻尼比等因素的敏感性后,给出了两种结构的参考响应谱和跨度、阻尼比修正系数,回归了参考响应谱包络线的方程,进一步给出了单人行走下楼板和人行天桥动力响应的简化计算方法,通过计算出的响应对结构进行舒适性验算。单人作用引起的结构振动问题的研究相对成熟,人群作用下结构的振动研究逐渐成为目前研究的重点。本文采用蒙特卡罗模拟技术解决了人群作用下楼板的竖向振动和人行天桥的侧向振动问题,主要包含以下两部分： (1)对楼板结构在不同人群密度下分别进行20000次蒙特卡罗模拟,得到了楼板结构的最大加速度和均方根加速度的均值、标准差、75%分位值和95%分位值,回归了动力响应的增大倍数与人数之间的表达式。改变楼板的跨度比和边界条件在相同的人群密度下分别进行20000次模拟,得到人群作用下楼板结构在不同跨度比下的边界条件修正系数。根据以上研究,通过简单的计算就可以求得结构相应的加速度响应,从而进行舒适度评价 (2)考虑人-桥相互作用下人行天桥的侧向振动。通过引入附加侧向行人作用,建立了人-桥动力耦合模型,在结构侧向失稳的临界人数范围内对不同的人群密度分别进行20000次蒙特卡罗模拟计算,得出了振动响应的增大随人数增长的函数关系。比较分析了考虑人-桥相互作用和不考虑人-桥相互作用时桥梁的动力响应,结果表明当人数超过20时,人-桥相互作用对振动的影响是不容忽略的。进一步总结了不同人数的情况下结构振动响应的计算方法,该方法可以为人群作用下人行天桥侧向振动舒适度的评价提供参考依据。论文通过反应谱法和蒙特卡罗模拟技术研究了大跨度楼板结构和人行天桥在人行激励下的振动舒适度问题,并给出了两种结构舒适度评价的一般方法,本方法理论上合理并且简便实用,具有良好的工程意义。本论文属于国家自然科学基金项目(编号：51168021)的组成部分。
[Abstract]:In recent years, with the development of structure to light, long span, and flexible direction, more and more projects are difficult to use due to the vibration comfort problem. Some buildings are reformed or rebuilt or even completely demolished. Thus, it can be seen that once the structure of the structure has a vibration comfort, the difficulty and cost will be greatly solved. Therefore, it is necessary to study the vibration comfort of the building structure. In this paper, the vibration of the floor and pedestrian bridge under human excitation is systematically studied in the light of structural dynamics, ergonomics and probability theory.
First, the design standards and evaluation methods of floor and pedestrian bridge vibration comfort are introduced in this paper. Then 30 human loads determined by the uniform test design method are used to construct the excitation function according to the Ellingwood method, and a large amount of calculation is given to the floor structure and the pedestrian bridge under single person by the Newmark algorithm. The vertical maximum acceleration response spectrum and the root mean square acceleration response spectrum of the floor structure under single moving load are given. The lateral maximum acceleration response spectrum and the root mean square acceleration response spectrum of the pedestrian bridge under the interaction of man and bridge are given. The response spectrum is given to analyze the sensitivity of the response spectrum to the structure's span, boundary condition, damping ratio and so on. The reference response spectrum and span of the two structures, the damping ratio correction coefficient and the equation of the reference response spectrum envelope are regress, and the simplified calculation method of the dynamic response of the single man walking floor and the pedestrian bridge is further given, and the structure is calculated by the calculated response.
The study of structural vibration caused by single action is relatively mature, and the research of vibration of structure under the action of crowds has gradually become the focus of research. This paper uses Monte Carlo simulation technology to solve the vertical vibration of the floor and the lateral vibration of the pedestrian bridge under the action of the crowd, which mainly includes the following two parts:
(1) 20000 times Monte Carlo simulation is carried out on the floor structure under the density of different population. The maximum acceleration and mean square root acceleration of the floor structure, the standard deviation, the 75% division value and the 95% division value are obtained, and the expression between the increasing multiplier and the number of the dynamic response is returned. The span ratio of the floor and the boundary condition are changed in phase. 20000 simulations are carried out in the same population density, and the boundary condition correction coefficient of the floor structure under the different span ratio is obtained. According to the above study, the corresponding acceleration response can be obtained by simple calculation, thus the comfort degree is evaluated.
(2) considering the lateral vibration of a pedestrian bridge under the interaction of man and bridge. By introducing an additional lateral pedestrian action, a dynamic coupling model of a man bridge is established. In the range of the critical number of the lateral instability of the structure, 20000 Monte Carlo simulations are carried out to the density of the different population respectively, and the function of the vibration response increases with the increase of the number of people. The relationship between the bridge interaction and the bridge interaction is compared and analyzed. The results show that the influence of the bridge interaction on the vibration is not negligible when the number of people is over 20. The calculation method of the structural vibration response is further summed up in the case of different number of people. This method can be used for the crowd. The reference for the evaluation of lateral vibration comfort of the footbridge is provided.
In this paper, the problem of vibration comfort of large span floor structure and pedestrian bridge under human excitation is studied by the reaction spectrum method and Monte Carlo simulation technique, and two general methods for evaluating the comfort degree of the structure are given. This method is reasonable in theory, simple and practical, and has good engineering significance.
This thesis is part of the National Natural Science Foundation of China (serial number: 51168021).
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.11;U441.3

【参考文献】