【作者】 韦金城；

【导师】 沙爱民；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2014， 博士

【摘要】 沥青路面半刚性基层疲劳预估模型一直沿用的单一疲劳指标模式，不能适应重载和气候环境综合作用下半刚性基层沥青路面结构性能评价的要求。半刚性基层沥青路面急需突破长寿命路面结构设计的技术瓶颈，主要是结构性能评价中反映实际状态的疲劳损伤模型及其支持参数。其建立方法和应用是半刚性基层沥青路面的共性关键技术。本文通过理论与实验研究，改进了半刚性材料室内疲劳损伤测试方法，提出了用弯拉模量衰减率和弯拉强度比两项指标联合表征的半刚性材料疲劳损伤模型，基于室内ALF加速加载试验和现场实体工程观测验证，得出了反映路面结构实际损伤状态的半刚性基层结构疲劳损伤模型及其支撑参数。针对现行半刚性材料疲劳试验结果离散性和变异性大的技术难题，通过对比试验分析，提出了用同层位梁试件弯拉强度确定疲劳荷载的疲劳损伤测试方法，提高了试验结果的可靠性；针对重复加载致梁体沿长度方向模量不均匀的问题，提出了测量梁试件中段1/3区域挠度差的重复加载弯拉模量测试方法，实现半刚性材料不同疲劳损伤程度弯拉模量的测试；基于重复加载疲劳试验和连续损伤力学原理，首次建立了用弯拉模量衰减指标和疲劳方程联合表征的半刚性材料疲劳损伤模型；为解决支撑疲劳损伤模型力学响应计算的结构模量参数取值问题，通过对不同试验理论与方法测试比较，提出了基于试件中段应变测量的半刚性材料单轴压缩弹性模量简单试验方法，提高了模量测试结果的可靠性，解决了现行试验方法模量参数与实际不符的技术难题；基于理论与现场检测验证，提出了半刚性材料层设计期末疲劳损伤状态下的有效模量确定方法，为结构损伤全过程分析参数输入提供依据；开发了适用于半刚性材料与结构在现场环境作用下的响应测试新技术，首次得到了半刚性基层结构现场温度变化引起的应力应变响应特征；首次综合重载ALF加速加载试验路与路面力学响应传感测试系统对半刚性基层疲劳损伤模型进行观测验证，明确了半刚性基层结构损伤演变过程及不同阶段的状态，提出了疲劳开裂产生阶段与裂缝扩展阶段时长的关系。更多还原

【Abstract】 Semi-rigid base is mainly adopted in high-grade highway asphalt concrete pavement.However, fatigue failure of asphalt concrete pavement with semi-rigid layer is serious dueto heavy traffic coupled with environmental effect. To break through the bottleneck of thedesign idea of long-term pavement structure for semi-rigid base asphalt concrete pavement,research must be conducted on the fatigue damage model and the relative parameter alongwith simulation of material and structure damage. The kernel of pavement structure designis the model of fatigue damage for semi-rigid materials. And its establishment along withapplying is the general key technology of asphalt concrete pavement with semi-rigid base.The project begins with study on the fatigue damage model of semi-rigid basematerials. And then research on verify the structure damage of semi-rigid base materials byALF and actual engineering research. From the research, A fatigue damage model whichreflects the actual damage status of pavement structure was established.The fatigue testing method that based on flexural strength (FS) determined by thebeam specimen sawed the geometric symmetry position from a larger beam is developedaimed at solving the problem of large discreteness and variability of the fatigue test results.The flexural stiffness modulus test method is developed by measuring the maximumdeflection difference between the middle third of the specimen, which has solved theproblem of the nonuniformity of flexural stiffness along the specimen subjected to repeatedload. The model of modulus attenuation that related to stress ratio is found for the first timebased on fatigue test and continuum damage mechanics. The simulating of the damageprocess of material and structure applying finite element and analysis method is done basedon model of modulus attenuation.To determine the modulus parameter in mechanical response analysis, the method ofcompressive elastic modulus test is developed by measuring the deformation of the middlethird part of the cylindrical specimen when subjected to determined load, which hasimproved the reliability of test results. The effective modulus magnitude of semi-rigidmaterials at the end of the design life is determined based on theoretical analysis andin-situ detection, which has provided basis for parameter input in damage analysis. Thefatigue damage model of semi-rigid base materials and structure was firstly investigatedand verified by the combination of heavy load ALF and mechanical response sensorssystems, the damage phases and the corresponding characteristics of semi-rigid base weredeterminded and the relationship between time of fatigue damage fist phase and secondphase was provided.更多还原