人行桥横向振动与减振控制技术研究

发布时间：2018-04-17 23:03

本文选题：人行桥 + 横向振动　；参考：《西安科技大学》2015年硕士论文

【摘要】：随着现代交通方式的不断发展和交通流量的与日俱增,人行桥的数量越来越多。人行桥的结构形式从单一的简支桥发展到现在的斜拉桥、悬索桥和拱桥;建桥材料从单一的木材发展到现在的混凝土、钢材、各类组合材料以及新型材料;桥梁跨径从几米到如今几十米甚至上百米。这些不仅促使人行桥向大跨、轻盈和柔美等方向发展,而且使人行桥更好的与周围环境相融合。但是这些新结构和材料使得人行桥固有的阻尼越来越低,很容易在人群荷载激励下发生过度振动,近些年来行人激励引起的振动事故屡见不鲜。起初人们只是关注了人行桥的竖向振动,认为竖向振动是人桥共振的主要原因。伦敦千禧桥发生横向过度振动才使人们开始关注桥梁横向振动,后续的研究证明桥梁横向振动比竖向振动更为严重,但各国规范在此处都是空白。因此非常有必要对人行桥的横向振动和控制措施进行深入研究。本文基于一座简支钢结构人行桥,利用有限元Midas Civil软件建模并进行桥梁模态分析,研究人行荷载激励下桥梁横向振动规律。提出临界人数概念,即人桥共振时对应的行人数量,推导临界人数的计算公式,目前通过计算临界人数来避免人桥共振是公认最有效的方法之一,而且可为桥梁的安全管制提供参考;进而计算临界行人数量荷载作用下桥梁动力响应,引入人行桥行人舒适度和舒适度指标,对该人行桥的动力响应进行评判,对于不能满足行人舒适度的桥梁需进行减振加固,本文基于结构耗能减振技术对该人行桥进行加固,拟采用调谐质量阻尼器进行减振控制,并分别采用单一调谐质量阻尼器(TMD)和多个调谐质量阻尼器(MTMD)进行加固,通过计算调谐质量阻尼器的相关参数并用软件进行模拟计算,对比两种加固的减振效果,并对两种方法进行综合的评价。
[Abstract]:With the development of modern traffic mode and the increasing of traffic flow, the number of pedestrian bridges is more and more.The structure form of footbridge has developed from single simply supported bridge to cable-stayed bridge, suspension bridge and arch bridge, and bridge construction material has developed from single timber to concrete, steel, all kinds of composite materials and new materials.Bridges span from a few meters to the present tens of meters or even hundreds of meters.These not only promote the development of pedestrian bridge to the direction of long span, lightness and softness, but also make the footbridge better integrate with the surrounding environment.However, these new structures and materials make the inherent damping of footbridge lower and lower, and it is easy to cause excessive vibration under crowd load. In recent years, the vibration accidents caused by pedestrian excitation are common.At first, people only pay attention to the vertical vibration of the footbridge, and think that the vertical vibration is the main reason of the bridge resonance.Due to the excessive lateral vibration of the Millennium Bridge in London, people begin to pay attention to the lateral vibration of the bridge. The subsequent studies prove that the lateral vibration of the bridge is more serious than the vertical vibration, but the national codes are blank here.Therefore, it is necessary to study the lateral vibration and control measures of footbridge.In this paper, based on a simply supported steel footbridge, the finite element Midas Civil software is used to model the bridge modal analysis, and the lateral vibration law of the bridge under the excitation of pedestrian load is studied.This paper puts forward the concept of critical number, that is, the number of pedestrians corresponding to the man bridge resonance, and deduces the formula of the critical number. At present, it is recognized that one of the most effective methods is to avoid the bridge resonance by calculating the critical number of people.And it can provide reference for the safety control of the bridge, and then calculate the dynamic response of the bridge under the action of critical pedestrian number load, introduce the pedestrian comfort and comfort index of the footbridge, and evaluate the dynamic response of the footbridge.For the bridge which can not meet the pedestrian comfort degree, vibration absorption and reinforcement are needed. Based on the structural energy dissipation vibration reduction technology, the bridge is strengthened, and the tuned mass damper is used to control the vibration.A single tuned mass damper (TMD) and a number of tuned mass dampers (MTMDs) are used to reinforce the vibration. By calculating the relevant parameters of the tuned mass dampers and using software to simulate and calculate, the effects of the two kinds of strengthened dampers are compared.The two methods are evaluated synthetically.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3;U448.11

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