【作者】 刘克非；

【导师】 徐志胜； 芮勇勤；

【作者基本信息】 中南大学 ， 土木工程， 2012， 博士

【摘要】 全球气候变暖的大背景导致各类极端天气气候事件频发。极端气候事件直接导致路面结构的损坏和病害的大幅增加,降低路面的使用性能和服务寿命,经济效益和社会效益损失严重。本文分别以南方地区极端低温(含冻雨、冰灾)气候、北方地区极端高温和夏季洪水气候为研究背景,以高速公路沥青路面为研究对象,综合现场调研、室内试验、数值模拟和理论分析方法,系统研究了各极端气候条件下高等级公路沥青路面破坏机理与修复技术。论文取得的主要成果如下：(1)针对作用于公路工程的特定环境,给出了三种极端天气气候事件(南方地区极端低温(含冻雨、冰灾)、北方地区极端高温和夏季洪水)的定义与作用范围,获得了各极端气候与常态气候的差异及其对沥青路面结构和交通运输产生的典型破坏类型和表现特征。(2)通过现场调研、室内试验和数值模拟,阐明了极端低温气候作用后南方地区沥青路面典型病害和产生原因,获得了AH-70、SBS和CMA沥青混合料不同冻融循环条件下的空隙率、低温弯曲应变、弯曲劲度模量和水稳定性,得出了各材料低温抗裂性能和冻融稳定性的衰减规律,建立了路面结构内区域性积水的冻胀模型,得到了冰冻作用下沥青路面局部积水结冰膨胀力学响应特征。(3)总结了极端高温气候下北方地区沥青路面典型破坏特征,获得了基质沥青、SBS、CMA结(混)合料极端高温条件下的车辙因子、蠕变劲度、动稳定度和抗剪参数。在计算各极端高温下沥青路面温度场分布的基础上,建立了不同路面结构形式、极端温度条件下结构层内永久变形量和剪应力间的关系,得到了重载高温条件下北方地区沥青路面破坏机理。(4)分析了北方地区沥青路面受夏季洪水气候作用后的典型破损特征和层间连接情况,获得了各层位材料受水浸泡后的强度和水稳定性衰减规律。建立了移动荷载作用下结构动力响应分析模型,得出了不同路面结构水-力耦合条件下的孔隙水压力,获得了洪灾后北方地区沥青路面产生结构型车辙的致灾机理。(5)基于对沥青路面现有病害处治方案的评价,分析了极端气候条件下沥青路面修补材料应具备的性能,提出了适宜修复各类典型病害的修补措施,明确了各典型病害最佳修补时间,提炼了裂缝封填和坑槽修补的施工工艺。采用寿命周期费用方法确定了极端气候灾害前沥青路面预防性养护最佳时机。研究成果可为提高路面结构设计的有效性和可靠性提供理论依据与数据支持,对减少和减轻各类病害,降低养护与维修成本具有积极的现实意义。进一步地,对我国现有路面结构与材料设计、施工和养护规范的修改和完善也具有重要的参考价值。更多还原

【Abstract】 Global climate warming is the background of all kinds frequent extreme weather climate events. Extreme weather event directly increase the damage and disease of pavement structure, reduce its service performance and service life, the economic efficiency and social efficiency suffer serious loss. This paper based on the southern area extreme low temperature climate (include freezing rain and ice disaster), northern area extreme high temperature and summer flood climate for research background, taking expressway asphalt pavement as the research object, synthesize methods of site investigation, laboratory test, numerical simulation and theoretical analysis, the failure mechanism and remediation technology of high-grade highway asphalt pavement which under various extreme climate conditions were systematically studied.The main achievements of the paper are as follows:(1) Aiming at the specific environment which is acting on highway engineering, the definition and action sphere of three extreme weather and climate events have been given, that is southern area extreme low temperature (include dreezing rain and ice disaster), northern area extreme high temperature and summer flood. The difference between each extreme climate and normal climate, and its typical failures and exprerssive characteristics to asphalt pavement structure and road transportation were obtained.(2) By means of site investigation, laboratory test and numerical simulation,the typical diseases and cause of south asphalt pavement which suffer extreme low temperature climate have been illustrated. The porosity, low-temperature bending strain, bending stifffness modulus and water stability of AH-70, SBS and CMA mixtures under different frost and thaw condition were obtained. The attenuation law of low-temperature crack resistance and freeze-thaw stability of each material were obtained. The pavement ice expansion model which concerned crack regional water in pavement structure has been built, and the mechanical response characteriatics of asphalt pavement local ice inflation under frozen action have been analyzed. (3) The typical damage features of north asphalt pavement which suffer extreme high temperature climate have been summarized. The rut factor, creep stiffness, dynamic stability and shear parameter of base asphalt, SBS and CMA binders and mixtures were obtained. Based on the temperature distribution of asphalt pavement under each extreme high temperature, the relationship between perment deformation and shear stress of structure layers which under different pavement structure and extreme temperature condition has been estabilished. The failure mechanism of north asphalt pavement which under heavy load and high temperature was put forward.(4) The typical breakage form and interlayer connection situation of north asphalt pavement which suffer summer flooding climate have been investigated and analyzed. The attenuation discipline of strength and water stability of each layer which suffered water immersion were obtained. The dynamic response model of pavement structure which under moving load was estabilished, and the pore water pressure of different pavement structure which under water-force coupling condition have been calculated. The disaster-causing mechanism of structural rutting of asphalt pavement in north region after was obtained.(5) Based on the present disease treatment scheme evaluation of asphalt pavement, the basic properties of repair material which appropriate each extreme weather condition have been analyzed. The suitable repair measures and optimum repairing time of typical diseases have been proposed, the construction technology of crack sealing and pothole repair were epurated. The best preventive maintenance time of asphalt pavement before extreme climate disaster has been determined by life cycle cost method.The research results can provide theoretical basis and data support to improve the effectiveness and reliability of pavement structure design, it also can alleviate pavement diseases, reduce the maintenance and repair costs. Furthmore, it has important reference value to revise and perfect the current design, construction and maintenance specification of pavement structure and material.更多还原