【作者】 涂帅；

【导师】 沙爱民；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2013， 博士

【摘要】 本文基于颗粒物质间的相互作用，采用室内试验、有限元模型分析和离散元模型分析等手段，在宏观和细观尺度上对高性能级配碎石基层的结构与性能进行系统研究。基于颗粒材料自锁的形成条件，提出采用逐级填充法和最大密度曲线理论进行级配碎石设计；对比分析了7种常见级配设计方法对级配碎石密度及空隙率的影响；提出了i法和逐级填充法能够使级配碎石具有较高的密度和合理的空隙率的级配。对不同空隙率的级配碎石材料进行渗透性能试验，提出基于渗透性能的最小空隙率要求；通过动态循环三轴试验，并根据轴向塑性应变提出了级配碎石材料的最大空隙率要求；对空隙率范围内的级配碎石材料的CBR进行了试验分析，提出了基于永久变形和渗透性能的高性能级配碎石材料的推荐级配；采用安定性理论对变荷载条件下级配碎石材料进行了安定性评价。采用室内试验获取的各种级配碎石的性能参数，建立级配碎石混合料的弹塑性连续介质有限元模型，从宏观尺度模拟分析了级配混合料的整体应力、变形的传递及分布，并对比了顶面荷载对模型内部应力及变形的影响。采用均匀化理论方法，建立级配碎石混合料的力学性能、变形特性等宏观动力响应与微观的颗粒间接触力、颗粒的位移等指标之间的联系，提出了级配碎石材料的多尺度关联方法。建立三维弹塑性有限元模型，在不同的荷载水平、结构层厚度、结构层模量等条件下，分别对设置高性能级配碎石过渡层和基层的沥青路面结构要应力指标进行了计算分析，并建立了影响因素与应力指标的回归方程；基于应力指标最小化，提出了设置高性能级配碎石过渡层和基层的沥青路面结构组合形式。采用带弯拉反射裂缝的基层和温缩裂缝的面层两种开裂方式建立仿真模型，对路面开裂前后级配碎石过渡层对应力指标的影响进行了对比计算，分析级配碎石层对路面裂缝扩展的影响。基于试验研究及模型的模拟分析，提出了具有较高的强度、抗变形能力以及良好的排水性能的高性能级配碎石基层的设计目标、设计指标、设计标准及设计方法，并从级配碎石的均匀性实现、施工厚度与结构层厚度关系、压实方法及压实度控制、施工质量检验等方面提出了对高性能级配碎石的施工工艺要求。更多还原

【Abstract】 Based on the interaction between granular materials, the indoor test, finite element model and discreteelement model are used to study the structure and properties of high performance graded crushed stonebase in macro-scale and macro-scale.To satisfy the self-lock condition between granular materials, gradation design method is proposed bygrading fill test and the theory of maximum density curve. The influence from7common grading designmethods on the density and void fraction are analyzed, and from the comparative analysis result, I methodand grading fill method could make the graded gravel has high density and rational void fraction.Permeability of graded gravel with various void content are tested, and the minimum void ratio isproposed. By the dynamic cyclic tri-axial test, the maximum void ratio is determined based on the axialplastic strain demand. The CBR of graded gravel within the rational void ratio scope are tested to confirmthe excellent mechanical performance, and the gradations of high performance graded gravel arerecommended. The stability of graded gravel under variable load conditions is evaluated.Using the performance parameters form indoor tests, the elastic-plastic continuum finite elementmodel is established, and the transmission and distribution of the stress and deformation in macro-scale areanalyzed. Using the homogenization theory method, the mechanical properties and deformationcharacteristics in macro-scale are related with the contact force between particles and displacement ofparticles in micro-scale, and the multi-scale correlation method of graded crushed stone material is putforward.Three-dimensional elastic-plastic finite element model is set up, in different load level, structure,layer thickness, structure layer modulus, the stress indexes of asphalt pavement with graded gravel astransition layer or base layer are analyzed, and the regression equations of stress indexes are established.Based on the minimum stress index, the structure combinations of asphalt pavement with graded gravel astransition layer or base layer are proposed. Simulation models with top-down crack in surface layer andbottom-up crack in base layer are established respectively, the stress indexes are calculated and comparedwith the initial value, to analyze the influence on the crack propagation from the graded gravel transitionlayer.From the experimental study and the simulation model analysis, the design goals, design index,design criteria, and design method of high performance graded gravel with high strength, high deformationresistance ability and good permeability are proposed. And the construction technology requirements inpreparation, transportation, paving and compaction are proposed.更多还原