轨道交通桥梁结构噪声的全频段预测、评价准则及控制策略研究

Track irregularity excitation causes vibration of the bridges, which then radiate noise, called structure-borne noise which is a cross of multi- direction and discipline. Based on 3-D train - track - bridge coupling vibration theory, Boundary Element Method (BEM) and Statistical Energy Analysis (SEA), this research puts forward a novel algorithm for predicting structure-borne noise of various rail transit bridges with a large frequency range, which will be compared with field measurements. The radiation mechanisms, spectrum characteristics, propogation laws and main influence factors of various typical bridges will be studied. By combining with subjective degrees of annoyance and objective indexes of sound equality, this research will establish a database of structure-borne noise of typical bridges, as well as the mathematical correlation models between subjective and objective evaluation. And then, the objective evaluation indexes and some threshold curves of structure-borne noise which are suitable to our Chinese people will be introduced. Aiming at the noise mitigation of Simply-supported prestressed concrete, continous prestressed concrete and steel-concrete composite box-girder, this research will start with three aspects: damping bearings and Viscoelastic constrained layer dampings, respectively. The coupling dynamic models between bridge structures and noise mitigation devices will be investigated, as well as the optimal matching parameters between them. At last, a comprehensive assessment will be done for the noise reduction effect. The research contents are closely associated with actual projects, which are basic and key problems. As a new cross-discipline, according to the research, the development of structure-borne noise of rail transit will be promoted, which undoubtedly have broad application prospects.

轨道不平顺激励引起桥梁结构振动，进而向空间辐射噪声，桥梁结构噪声是多方向、多学科的交叉。基于列车-轨道-桥梁空间耦合振动理论、边界元法和统计能量分析，研究桥梁结构噪声的全频段预测算法，并结合现场试验进行验证，揭示典型桥梁结构噪声的产生机理、频谱特性、传播规律和主要影响因素。采用主观烦扰度和客观声品质参量评价相结合的方法，建立典型桥梁结构噪声实测数据库和主、客观评价数学关联模型，提出适合我国人群特点的桥梁结构噪声客观评价量及其阈值曲线。针对混凝土简支（连续）箱梁和钢-混结合箱梁，从减振支座和粘弹性阻尼约束层两方面入手，建立桥梁结构与降噪装置的耦合动力模型，提出各降噪装置与桥梁结构的合理参数匹配关系，并综合评价降噪效果。本研究内容是与工程紧密联系的几个带有基础性的关键问题，通过本研究能促进轨道交通桥梁结构噪声这一新兴交叉学科的发展，研究成果具有广泛的应用前景。

本研究针对列车通过轨道交通桥梁结构时引起的振动和噪声问题，采用现场试验、数值模拟和理论分析相结合的方法开展研究，主要的研究成果包括：1）基于列车-轨道-桥梁耦合动力学理论、边界元法、统计能量分析和振动声辐射理论，提出了轨道交通混凝土桥梁结构噪声预测方法、桥梁结构噪声的混合FE-SEA预测方法、铁路钢-混结合梁桥结构噪声预测方法，研究了轨道交通典型桥梁结构的声辐射机理、频谱特性和空间分布规律；2）基于列车-轨道-桥梁耦合动力学理论、统计能量分析和模态应变能法，提出了约束阻尼层敷设于铁路钢-混结合梁桥结构噪声辐射的分析方法，并在国内首次开展了高速铁路钢-混结合梁桥敷设约束阻尼层的减振降噪机理和方法研究；3）基于列车-轨道-桥梁耦合动力学理论、薄层单元法和容积法，提出了高速铁路桥梁段地面振动预测方法，研究了高速铁路桥梁段地面振动特性和传播规律；4）在国内首次系统、大规模开展了轨道交通桥梁结构噪声现场测试，分析总结了轨道交通高架桥梁结构的声辐射机理、传播规律，建立了典型桥梁的结构噪声实测数据库；5）基于锤击试验和有限元分析，提出了高速铁路混凝土箱梁振动传递特性分析方法；6）基于现场试验、振动模态分析和空腔声模态分析，探明了箱梁内“空腔共鸣”现象的产生机理；7）采用数值模拟的方法探明了轨道结构形式对轨道交通混凝土箱梁振动和噪声的影响机理；8）开展了高速铁路半封闭和全封闭声屏障降噪特性的试验研究。通过本研究加深了对轨道交通桥梁振动特性和噪声辐射机理的理解，研究成果为轨道交通桥梁减振降噪理论及工程应用提供了科学的理论依据。