【作者】 蔚旭灿；

【导师】 郑传超；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2008， 博士

【摘要】 本文应用数学力学方法，分析了沥青路面结构在三种状态下的性能，即常温下的一般受力状态、高温下的粘弹性能和低温下的抗开裂性能。对于常温状态下的沥青路面结构，利用弹性层状体系理论，分析了层状路基合成模量的计算方法，得到了双层弹性层状弹性体系当量模量诺模图，并分析了当量模量的影响参数。对柔性承载板、刚性承载板作用下的当量模量，以及规范上的当量模量计算公式进行了对比，发现三种情况的差异较大，特别是规范上的计算公式甚至有得到负值模量的情况，严重与实际不符。分析了长寿命路面结构的概念和含义，以及设计指标的合理选取。对两种长寿命路面的结构形式进行了参数分析，得到了设计指标最为敏感的影响参数，为陕蒙路提出了试验路方案和推荐型式。提出了路面结构和造价的优化规划方法，对规定参数范围和设计指标的一个例子进行了优选，根据各结构层的造价函数，对目标函数为造价的规划进行了计算。根据对应原理，求解了粘弹性半空间体，对其表面位移进行了参数分析，发现对不可回复粘性系数最为敏感，而对可回复弹性和粘性系数最不敏感。通过拉普拉斯逆变换的数值法，求解了粘弹性双层体系，总结了利用对应原理和拉普拉斯逆变换数值方法求解多层体系的一般方法。以三层体系的沥青路面为例，为沥青面层提出了三种不同的非线性粘弹性模型，以考虑沥青面层随着荷载次数增加的固结效应。提出了车辙的计算方法，计算了车辙与荷载作用次数的关系，分析了车辙的各种影响因素。对于路面材料的抗开裂性能，分析比较了各种评价试验方法，着重对SCB试件进行了分析，利用有限元方法计算SCB试件裂尖附近的应力和位移分布，根据断裂力学理论求得了不同裂缝长度时的应力强度因子，拟合了计算公式，讨论了其影响因素。对路面结构的芯样和试验室的两种试件进行了SCB试验，得到了它们0℃和-20℃下的断裂韧度。对于路面结构的反射裂缝和自上而下裂缝，建立了有限元分析模型，分析计算了它们在5℃、20℃下Ⅰ型、Ⅱ型开裂的应力强度因子，拟合了计算公式，对四种面层厚度不同的情况进行了对比，分析了不同面层模量对应力强度因子的影响。利用描述裂缝扩展速率的Paris公式分析了Ⅰ型开裂裂缝的寿命，得到了裂缝长度与荷载作用次数的关系曲线，对不同面层厚度、不同裂缝类型的寿命进行了比较。更多还原

【Abstract】 In this paper,the performance of asphalt pavement under the condition of ambientternperature,high temperature and low temperature was analyzed by the methods ofmathematics and mechanics.According to the elastic layers system theory,the equivalent elastic modulus oflayed-foundation of asphalt pavements under ambient temperature was formulated andcalculated,and the parameters influencing it were analyzed.The comparision of equivalentelastic modula under flexible and rigid bearing plate and got by the specification showed thethree methods were difference each other very much,especially the method in thespecification existed a fatal error that it can lead the modulus to be a negative,which wasimpossible in fact.This paper discussed the idea and signification of long-life pavement and its design target.The structures of two kinds of long-life pavements were analyzed,and the most sensitiveparameters of its design target.Based on the analysis,four kinds of test road structure wereproposed for the Shan-Meng highway.Optimizing methods of pavements structure and roadcost were used to analyze the long-life pavements.The visco-elastic half space was solved according to the correspondence principle,andthe influencing parameters of surface displacement were analyzed;the results indicated thatthe surface displacement’s most sensitve parameter was the inrecoverable viscocitycoefficient,and the two insensitive paramenters were the recoverable elasticity coefficientand recoverable viscocity coefficient.The two-layer visco-elastic system was solved by thenumerical inversion of Laplace transform,and the general solution of multilayeredvisco-elastic system was concluded.Taking the three-layer visco-elastic asphalt pavement asan example,three nonlinear visco-elastic models were introduced to consider the asphaltlayer’s consolidation with the increasing of load times.A computing method of rut wasproposed to analyze the relation between the rut and load times,and the influence factorswere also studied.As for the anti-crack performance of asphalt concrete,several test methods werediscussed and the emphase was put on the SCB(Semi-Circular Bending)specimen.The stress intensity factors of the cracks in SCB specimen were calculated by the fracturemechanics theory and FEM(Finite Element Method);its fiting formula was got and itsinfluence factors were discussed.The SCB specimens from pavements and laboratory weretested at 0℃and-20℃,and their fracture toughnesses were got.As for the reflective crackand top-to-down crack in the asphalt pavements,FEM models were constructed for them,andtheir stress intensity factors at 5℃and 20℃were calculated and fitted.The results of fourthicknesses of asphalt layer were analyzed and compared,and the effects of asphalt layermodulus on crack’s stress intensity factor were discussed.Using the Paris law,the relationbetween load times and crack length forⅠtype cracking was obtained,and the lifes ofreflective cracks and top-to-down cracks in asphalt layer with different thickness wereanalyzed.更多还原