【作者】 高伟；

【导师】 贾艳敏；

【作者基本信息】 东北林业大学 ， 载运工具运用工程， 2011， 博士

【摘要】 水泥路面是公路路面的主要铺装形式之一,具有承载能力强、稳定耐久、夜间视线好、环保,无车辙、推移或拥包病害等优点,20世纪80年代之后在我国得到了广泛应用。修筑稳定耐久、功能良好的水泥混凝土路面,对于发挥我国水泥资源供应充足的优势,保障交通运输和区域经济的可持续发展具有积极作用。但在黑龙江省以季冻区为主的高纬度、低海拔环境条件下,水泥路面较早地出现了横向及纵向开裂、断角、错台等病害,同时平整度、舒适性衰减严重,正常使用时间普遍不足设计基准期的50%。路面结构性病害长期存在,不仅给维修养护带来很大困难,而且严重影响了路面的使用功能和使用寿命,已成为制约公路水泥路面发展应用的技术难点。提高缩缝传荷体系的传荷能力,是维持路面板块之间荷载传递、提高路面承载力、减少结构性损坏,以及改善基层与面层板的受力状态、延长路面使用寿命的重要技术途径。但由于多种因素的影响,尽管对接缝传荷体系重要性的认识在不断加深,国内在相关研究和应用方面却一直滞后。为此,本文在分析比较国内外“普通水泥混凝土路面”结构设计差异的基础上,通过路面结构性病害的调查总结和试验观测,针对黑龙江省公路水泥路面结构性裂缝的具体表现形态,利用有接缝水泥混凝土路面三维有限元分析方法和迈因纳(Miner)线性累计损伤理论,研究缩缝传荷对水泥路面结构性损坏的影响方式,并探讨优化缩缝传力杆传荷体系。通过分析不同方法所考虑的水泥路面结构设计的影响因素,明确了国内外现行水泥路面结构设计方法中对路面接缝因素处理方式的不同之处,指出我国现行结构设计方法中对水泥路面横向缩缝传荷因素的考虑仅限于路面应力验算时的临界荷位的确定,但是该临界荷位所控制的疲劳裂缝和普遍存在的纵向裂缝有明显的不同。研究表明,在水泥路面的结构性损坏中,横向裂缝和纵向开裂是出现较早、普遍存在、所占比重最大的两种主要损坏形式,破碎板亦是由该两种裂缝发展而成。如果计入与之有关的破碎板和路面断角损坏,合计病害比重可高达96%。尽管结构性裂缝的病害原因比较复杂,但其共同点是与路面的接缝(主要是横向缩缝)的传荷状况有关；调查测试的水泥路面完好板块横向接缝中,缩缝传荷能力不足的为6.56%,缩缝传荷状况良好的占93.44%。表明黑龙江省现有水泥路面结构性病害的出现与缩缝传荷状态有密切关系。验算和观测表明：威斯特卡德(Westergaard)解析公式、EverFE三维有限元分析方法、我国公路水泥混凝土路面结构应力计算方法之间有着良好的对应性和符合性。论文分析了黑龙江省水泥路面疲劳开裂的影响因素和可能的表现形态。通过试验观测,利用迈因纳(Miner)线性累计损伤理论和三维有限元分析程序对水泥路面的荷载疲劳应力进行了分析。结果表明黑龙江省水泥路面预切缩缝宽度的变化在0～3.5mm之间,集料嵌锁型缩缝的传荷能力及其耐久性将随缝隙宽度的增加而迅速降低。增设缩缝传力杆后,接缝宽度的变化对缩缝传荷能力及其耐久性的影响大大降低,缩缝传荷系数能够相对稳定地维持在较高的水平。设传力杆时,板底最大拉应力减小,受缩缝宽度变化的影响程度较低；无传力杆缩缝的板底拉应力较大,并容易受到缩缝宽度变化的影响。传力杆缩缝传荷体系强化了路面板块之间的联合受力状态,有利于减少相邻板的差异沉降、缓解因路面后期错台产生的车辆震动,保持路面的平整度和行车的舒适性。根据车辆轮迹横向分布和缩缝传荷特点进行的疲劳应力分析,表明黑龙江省现有公路水泥路面纵向裂缝和横向裂缝都有发生的可能,但由于横缝边缘附近产生的疲劳度要大于纵缝边缘中部横断面处的疲劳度,因此,在实际使用的水泥混凝土路面上,出现纵向裂缝的可能性目前大于出现横向裂缝的可能性。采用缩缝传力杆体系可以明显降低水泥路面缩缝边缘附近的荷载疲劳度,疲劳度峰值降低幅度约在15.3-25.0%之间。即采用缩缝传力杆传荷体系能够有效降低或延缓水泥路面纵向疲劳裂缝出现的几率及出现时间。论文采用布拉德伯利传力杆验算公式、Visual Basic 6.0编程和三维有限元分析程序EverFE,分析传力杆的直径、长度、设置间距,以及对板底拉应力和缩缝传荷能力的影响等。研究认为传力杆的长度与直径之比为18.0时,传力杆传荷体系的“需要有效系数”最小,对应的缩缝传荷体系效率较高；推荐在路面板厚度≤24cm时,传力杆间距取30cm；当面层板厚度>24cm时,建议传力杆最大间距取40cm,可减少约27%的缩缝传力杆钢筋用量。本文研究内容对减少水泥混凝土路面的结构性损坏,以及正确认识和评价水泥路面的结构耐久性及工作状态具有积极作用;有利于降低公路建设和交通运输的周期成本,具有重要的社会意义和良好的社会经济效益。更多还原

【Abstract】 Cement concrete pavements are the main pavement form of hignway, possessing excellence of strong carrying capacity、stabilization and durability、fine sight in night、protecting environment、without track、process and bump, applied abroad in our country after 20 century 80 years, construct stabilization and durability、well function cement concrete pavement possessing active effection on exerting superiority of plenty cement resource, ensuring transportation and persistence development of district economy. Under circumstance of high latitude、low altitude seasonally frozen area in Heilongjiang province. Cement concrete pavements appeared traverse and longitudinal Crack、corner breakage、faulted joint disease. Planeness、comfort decline severity, common usage life lack 50% of design norm life. Pavement structural disease exist long,bring great difficulty in repair and maintain, affect function and longevity of pavement,became the technic difficulty of development application of concrete pavements.Enhance load transferring ability of contraction joint transferring system are important technic measure of maintain load transferring between slab、enhance carrying capacity of pavement、reduce structural breakage、improve bearing condition of base and slab、prolong longevity of pavement. Because of multiple factor affected, though adding understanding importance of joint transferring system, relative research and application always lag behind in our country. The article based on analyse and contrast of difference in structure design of common cement concrete pavement, by the investigation and observation of pavement structural disease, aim at appearance shape of highway cement concrete pavement structural crack in Heilongjiang province, apply finite element analysis method of joint cement concrete pavement and Miner linear accumulative damnify theory, research influence mode of joint load transferring to cement pavement structural breakage, discussion of optimize joint dowel bar load transferring system.By analyse Influence factor of different means considering cement pavement structure design, definite difference disposal mode of pavement joint factor in cement concrete pavement structure design method of nationnal and international, indicate that consideration of cement pavement traverse joint load transferring factor in national structure design method only limit to fixing critical load position when pavement stress compution, but fatigue crack controled by this critical load position have obvious differenence with ubiquitous longitude crack.Research indicate, in cement pavement structural breakage,traverse and longitude crack are main breakage form that appeared earlier、ubiquitous、most proportion. Crash slab also developed by the two crack. If count in relative crash slab and corner breakage, total disease proportion reach to 96%. Though disease reason of structural crack is complicated, but common point is relate to load transferring condition of pavement joint(mostly traverse joint); in the traverse joint investigation of cement pavement fine slab, joint load transferring ability deficient is 6.56%, joint load transferring in fine condition is 93.44%. Indicate appearance of cement concrete pavement structure disease have intimate relation with joint load transferring condition in Heilongjiang province. Compution and observation indicate:Westergaard parse formulation^ EverFE finite element analysis method、structural stress compution method of highway cement concrete pavement in our country have benign corresponding and accordance.The article analysed influence factor and possible appearance shape of cement pavement fatigue crack in Heilongjiang province. By test and observation, using Miner linear accumulative damnify theory and finite element analysis programm to analyse load fatigue stress of cement pavement.The result manifest that joint breadth changed between 0-3.5mm of cement pavement in Heilongjiang province, joint load transferring ability and durability of aggregate interlock mode reduced prompt along with increase of joint breadth.After setting joint dowel bar, change of joint breadth influence on joint load transferring ability and durability reduced greatly, joint load transferring coefficient maintain stable at a high level. When setting dowel bar, maximal tensile stress of slab bottom reduced, influence extent of joint breadth change suffered less; tensile stress of slab bottom bigger of joint without dowel bar,easily influenced by joint breadth change. Dowel bar load transferring system strengthen bearing condition of pavement slab, in favor of reducing different subsidence of border slab, alleviate vehicle shake caused by faulted joint, maitain planess of pavement and travelling comfort.According to vehicle trace traverse distribution and joint load transferring character, we proceed analysis of fatigue stress. Indicate that Highway cement pavement have likelihood of longitudinal crack and traverse crack, but because of fatigue degree at traverse joint edge bigger than traverse Section of Longitudinal Joint center. For cement concrete pavement, likelihood of longitudinal crack bigger than traverse crack. Apply dowel bar load transferring system may reduce load fatigue degree of joint edge, fatigue degree peak value reduce extent between 15.3-25.0%. Apply dowel bar load transferring system can reduce and delay appearance possibility and time of longitudinal fatigue crack.The article using Bradbury dowel bar computation formulation、Visual Basic 6.0 programme and finite element analysis programm EverFE, analyse length, diameter and setting space of dowel bar, and influence on tensile stress of slab bottom and joint load transferring ability. Research indicate when the ratio of length and diameter is 18.0, requisite rvailability roefficient of dowel bar load transferring system is least, joint load transferring system efficiency is higher; suggested that when thickness of pavement≤24cm, dowel bar setting space take 30cm; when thickness of pavement>24cm, dowel bar setting space take 40cm, may reduce 27% dosage of dowel bar steel.The article research content have active effection on reducing structural breakage of cement pavement, understand and appraise structural durability and working condition of cement pavement; in favor of reducing highway constuction and transport cycle cost, have important social meaning and benign social economical benefit.更多还原