基于三维网联模型的钢桥面铺装耦合动力行为特性与演化机理研究

The dynamic response of the steel deck pavement is a key issue of the intersection of bridge engineering and road engineering. The purpose of this research is to study the evolutionary mechanism of pavement dynamic behavior under multi-scale coupling, and to provide the theoretical basis for solving the problem of premature cracking of steel bridge decks. Based on the structural response, the multi-scale bridge modeling will be studied, so that the low frequency dynamic characteristics of the whole bridge and the medium/high frequency excitation in beam-plates system and the vehicle could be included in the analysis of the multi-scale pavement coupling behavior, and that the lack of the pavement characteristics during the normal bridge design process could be avoided. Then, based on the constitutive mechanism of composite materials, a three-dimensional network model will be established to characterize the microscopic dynamical constitution, which can express solve the viscoelastic behavior in three dimensional space. Furthermore, the relationship between microscopic constitution and macroscopic response of pavement material will be studied and the deterioration law of the pavement will be obtained through the fatigue test of variable frequency loading. The structural dynamic response and material fatigue properties will be improved through the asphalt mixture composition performance, skeleton configuration and other characteristics. This will provide the theoretical foundation for the pavement material design based on the dynamic characteristics, and provide technical support for improving the service life of steel bridge deck pavement and reducing the adverse social impact caused by the frequent maintenance.

钢桥面铺装体系动力学响应是桥梁及道路交叉领域的关键问题之一，本课题旨在研究多尺度耦合作用下的铺装动力行为演化机理，为解决钢桥面早期开裂提供理论依据。从结构响应入手，研究多尺度整桥模型的构建方法，将整桥低频振动、梁板体系及车辆的中高频激励纳入铺装动力耦合分析中，改进桥梁研究中忽略铺装特性的不足；从复合材料构型机理入手，建立三维网联模型，解决铺装粘弹性行为空间表达的难题；在此基础上，建立铺装材料微细观结构尺度与宏观尺度的联系，通过变频变幅疲劳加载试验获取铺装动力衰变规律；通过混合料组分性能、骨架构型等特性综合改善结构动力响应与材料疲劳性能，为基于动力评价指标的铺装材料设计提供理论基础，并为提高钢桥面铺装的寿命、减轻维修频繁造成的不利社会影响提供技术支撑。

本课题构建了车辆（车队）-铺装-索梁耦合的整桥动力模型，包括三个层次：反映索-梁-塔结构体系特征的整桥动力模型，采用板壳单元的钢箱梁节段模型，以及包含铺装的正交异性钢桥面体系实体模块；获取了铺装动态响应的不利梁段，分别研究了整桥低频振动以及局部梁段高频振动对铺装的动力影响系数。从组分特性与骨架构型等微细观层面揭示沥青混合料在动态域内的动力本构属性，构建了不同的三维网联模型表征各组分，在此基础上推演沥青混合料“体元”的动力本构参数；通过沥青混合料组分性能、体积分数、分布特征等组成特性进一步推知铺装层的动态模量、阻尼、耗散率等动力特征参数。开展混合料试验和动态监测，结合有限元内聚力模型结果进行相关性分析，界定了应变场启裂门槛值；基于循环荷载试验并运用主曲线理念从宏观材料层面获得沥青混合料的寿命预估方程。设计开发了能反映钢桥面铺装体系两种真实开裂模式的复合结构试验，并基于细观层面研究了钢桥面铺装及粘结界面开裂的门槛值；解决单质裂纹和界面裂纹扩展、夹杂体边界逼近、裂纹面接触以及裂纹面粘聚阻裂等问题，发展了适用于钢桥面铺装细观开裂问题的3D扩展有限元模拟方法，以准确模拟铺装体系三维裂纹面扩展过程，揭示其开裂机理和发展规律；建立了复合梁细观裂纹扩展与钢桥面铺装梁段宏观断裂之间的联系，明确了两种复合梁适用的工程场景。研发了新型热固性环氧沥青，探索其动力特性试验方法和性能表征指标，以匹配桥面铺装动力特性要求；基于耐久性要求对新型热固性环氧沥青开展了纳米改性研究，采用金属离子配位法制备了纳米改性剂并对环氧沥青进行进一步修饰，从而提高了其变形能力和耐久性；并在桥面铺装日常养护工程开展了应用与检验。该研究成果构建了桥面铺装多尺度动力分析模型，提出了能反映铺装材料粘弹性的空间本构表达，从宏细观提取了铺装及粘结层的断裂准则，为完善铺装结构动力学设计方法以及提升材料抗裂性能提供了理论参考和应用建议。