抚顺地区级配碎石倒装式路面结构力学性能研究

发布时间：2018-02-24 10:52

本文关键词： 倒装式路面结构路用性能力学响应疲劳性能　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：长期以来,由于半刚性基层拥有较大的强度与刚度,较高的承载能力、荷载扩散能力和抗行车疲劳性能等优点,被广泛应用于抚顺地区各级公路沥青路面的建设中。然而随着半刚性基层的广泛使用,其难以克服的缺点逐渐显现,很多研究者把目光转向了倒装式路面结构、柔性基层路面结构等新型路面结构。本文依据抚顺地区实际情况,进行了倒装式路面结构的室内路用性能试验,并对其力学响应情况及疲劳性能进行了研究。通过室内试验得到:骨架密实型级配碎石动回弹模量为112.7MPa、静回弹模量为334MPa;连续型级配碎石动回弹模量为116.5MPa、静回弹模量为362MPa。通过室内CBR试验得到:骨架密实型与连续型级配碎石CBR值分别为123.8%、101.75%,骨架密实型级配碎石的CBR值较大,验证了其具有良好的承载力。运用MTS810材料试验机对级配碎石永久变形进行研究,研究表明:随荷载作用次数的增加,骨架密实型与连续型级配级配碎石粒料的轴向永久变形逐渐增加,当重复荷载作用到达1000次时,永久变形量基本稳定;随应力逐渐增加试件的累积变形速率也相应增加,当达到一定作用次数时,永久变形将不继续增加。通过ABAQUS模拟得到:倒装式路面结构不仅能够防止半刚性基层反射裂缝的产生,同时在受力上表现为受力更加均匀,直接从根源上减少了半刚性基层开裂的可能。通过调整厚度和模量进行力学响应分析得到:中、轻交通的级配碎石层推荐厚度是110~140mm,推荐施工达到的模量是350~450MPa。采用NSOFT软件进行倒装式和半刚性基层路面结构疲劳性能分析,从面层损伤程度分析:倒装式路面结构大于半刚性路面结构,但是倒装式路面结构的沥青混合料面层与半刚性路面结构沥青混合料面层的疲劳损伤在同一数量级上,表明二者的疲劳性能相差不大,两者的水泥稳定碎石层疲劳损伤程度比较相近。本文的研究成果为级配碎石倒装式路面结构的推广应用提出了一定的基础性的认识,可以为设计和进一步研究工作提供参考。
[Abstract]:For a long time, semi-rigid base has many advantages, such as high strength and rigidity, high load-carrying capacity, load diffusing ability and anti-fatigue performance, etc. It has been widely used in the construction of asphalt pavement at all levels in Fushun area. However, with the extensive use of semi-rigid base course, its insurmountable shortcomings gradually appear, many researchers have turned their eyes to the inverted pavement structure. According to the actual situation of Fushun area, the indoor pavement performance test of the inverted pavement structure is carried out. The mechanical response and fatigue properties of the macadam are studied. The results of laboratory tests show that the dynamic resilience modulus of the dense graded crushed stone is 112.7MPa, the static elastic modulus is 334MPa, the dynamic springback modulus of the continuous graded crushed stone is 116.5MPa, and the static springback modulus is 116.5 MPa. The results of laboratory CBR test show that the CBR values of skeleton dense grained crushed stone and continuous graded crushed stone are 123.8and 101.75, respectively, and the CBR value of skeleton dense graded crushed stone is larger than that of continuous graded crushed stone. It is proved that it has good bearing capacity. The permanent deformation of graded crushed stone is studied by MTS810 material testing machine. The results show that: with the increase of the number of loads, The axial permanent deformation of the gradation grained crushed stone with dense skeleton and continuous gradation increases gradually, and when the repeated load reaches 1000 times, the permanent deformation is basically stable, and the cumulative deformation rate of the specimen increases with the increasing of the stress. When a certain number of actions are reached, the permanent deformation will not continue to increase. Through ABAQUS simulation, it is concluded that the inverted pavement structure can not only prevent the formation of reflective cracks in semi-rigid base, but also show a more uniform force on the force. The possibility of cracking of semi-rigid base is reduced directly from the source. By adjusting the thickness and modulus of the base, the following results are obtained:. The recommended thickness of graded crushed stone layer for light traffic is 110 ~ 140mm, and the recommended modulus of construction is 350 ~ 450MPa. the fatigue performance of pavement structure with inverted and semi-rigid base is analyzed by NSOFT software. From the analysis of the damage degree of the surface layer: the inverted pavement structure is larger than the semi-rigid pavement structure, but the fatigue damage of the asphalt mixture surface layer of the inverted pavement structure is the same order of magnitude as that of the semi-rigid pavement structure asphalt mixture surface. The results show that the fatigue performance of the two is not different, and the fatigue damage degree of the cement stabilized crushed stone layer is similar. The research results of this paper provide a certain basic understanding for the popularization and application of graded crushed stone inverted pavement structure. It can provide reference for design and further research.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.2

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