【作者】 廖丹；

【导师】 邓洪亮；

【作者基本信息】 北京工业大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 为了获得较高的承载能力及减小沥青面层厚度,我国高等级公路多采用半刚性基层。反射裂缝是半刚性基层沥青混凝土路面的常见病害,反射裂缝的出现不仅影响路面的美观和行车的舒适性,更重要的是大大地缩短了路面的使用寿命。交通荷载和温度荷载是导致反射裂缝形成和扩展的主要因素。本文以京珠国道主干线漯河至驻马店高速公路路面病害整治项目为依托,运用线弹性断裂力学理论及有限元法对反射裂缝的扩展机理进行了全面分析,并对运用智能合金复合夹层材料防治路面反射裂缝新技术进行了理论和现场试验研究。首先,运用断裂力学理论对反射裂缝尖端应力场的奇异性进行了描述,建立了平面断裂问题应力强度因子的数值解。介绍了ANSYS有限元分析软件,指出用其进行裂缝尖端应力强度因子计算是适用和高效的。其次,运用有限元软件ANSYS计算了裂缝尖端应力强度因子和面层内的应力,对基层含贯通裂缝的路面在交通荷载及温度荷载作用下的结构反应进行了深入分析。把交通荷载分为对称荷载和偏荷载两种情况,计算了裂缝尖端的应力强度因子,并对路面结构面层、基层参数变化对其的影响进行了分析。对路面突然降温时的温度场进行了数值模拟,计算了温度应力作用下反射裂缝尖端的应力强度因子,并对其进行了参数分析。接着对反射裂缝在交通荷载与温度荷载耦合作用下的裂缝扩展模式进行了研究。再次,介绍智能合金材料SMA及超薄应力吸收层艾赛克(英文简称ISCA),根据漯驻路的实际路面结构建立计算模型,并运用有限元软件ANSYS计算了铺设ISCA复合夹层的路面结构在交通荷载、温度荷载作用下裂缝尖端的应力强度因子和面层底部的应力。计算结果显示ISCA复合夹层对面层底部应力集中有较好的消散作用,能够抑制或者延缓反射裂缝向面层扩展。在讨论复合夹层的铺设位置对抑制反射裂缝扩展效果影响的同时,对夹层参数变化所造成的影响也进行了分析,提出了一套可供实际操作的反射裂缝防治方案。最后,结合现场试验及后续观测对理论分析结果进行验证,得出ISCA复合夹层防治反射裂缝是可行和高效的结论。通过以上工作,为作相关的后续研究及技术推广提供参考。更多还原

【Abstract】 In our country, to get stronger base and reduce the thickness of HMA layers, semi-rigid base is widely used in highways. Reflection cracks are common diseases of semi-rigid base asphalt pavements; they not only affect road appearance and riding comfort, but also shorten pavement service life excessively. Traffic load and temperature load are two main factors accounting for its formation and propagation. This paper bases on Luohe to Zhumadian highway pavement disease treatment project the Beijing-Zhuhai national trunk highway. In this Paper, linear fracture mechanics and finite element method are employed to give a full analysis to the mechanism of reflective crack’s propagation and the effectiveness of intelligent materials alloy sandwich control surface reflection is studied as well.Firstly, after depicting the singularity of stress field at the top of crack, the finite element method to calculate stress intensity factor of plain fracture problems is founded. Then it introduces the ANSYS finite element analysis software, and pointed out that it is applicable and efficient to be used to calculate the crack tip stress intensity factor.Secondly, the structural response of pavement surfing reflective cracking is deeply analyzed in terms of traffic load and thermal load. As for traffic load, two situations were analyzed, symmetrical load and asymmetric load, in each of them, crack tip stress intensity factor were calculated, and also the effect of structural parameters were analyzed. Pavement’s temperature distribution field when suffering sudden temperature dropping was numerical simulated. Crack tip stress intensity factor caused by thermal stress were computed, structural parameters’sensitivity analysis were made as well. Then, reflective crack’s propagation model under traffic load coupled with temperature load was analyzed.Thirdly, the intelligent materials alloy SMA and ISCA thin stress absorbing layer are introduced. According to the actual pavement structure of the Luohe to Zhumadian highway, the calculation model is set up. And the finite element software ANSYS is used to calculate the crack tip stress intensity factor of the pavement structure in terms of traffic load and thermal load. The results of the analysis showed that the ISCA composite sandwich had a better dissipation of crack tip stress intensity factor, and can inhibit or retard reflective cracking expand to the surface. During the discussion of the stress dispersing effect that the ISCA composite sandwich specific location, while the parameters of the sandwich change impact analysis is also carried out. At last, a set for the actual operation of the reflective crack control programs is proposed.Finally, combined with field testing and follow-up observation that the theoretical analysis results are verified, and the ISCA composite sandwich controlling the reflective crack is feasible and efficient. Through the above-mentioned work, the relevant reference for the follow-up study is provided.更多还原