【作者】 杨雅萍；

【导师】 原喜忠；

【作者基本信息】 长安大学 ， 材料学， 2010， 硕士

【摘要】 路基和垫层及底基层构成了的路面支撑系统,其结构参数直接影响路面的受力状态及长期性能。由于高地下水位地段粉土路基经常处于潮湿状态,承载力较低,无法满足路基路面设计要求,有必要对路床进行固化处理,并与路面基层共同形成一个稳定坚固的支撑体系,因此,本文基于沥青路面的长期性能对潮湿路段的路面支撑结构进行了综合优化设计。本文首先基于非饱和土理论并利用已有模型对高地下水位地段粉土路基含水量和路基回弹模量进行分析和预估。利用有限元分析建立了一般沥青路面和长寿命沥青路面土基顶面压应变与路表弯沉之问的相关关系,基于已有的弯沉-轴载累积作用次数的关系,建立土基顶面压应变-轴载累积作用次数关系(土基顶面压应变设计方程)。本文利用有限元分析了路面支撑系统参数对一般沥青路面与长寿命沥青路面受力状态和长期性能的影响。分析了土基模量、底基层模量及厚度、路床处理层模量及厚度对沥青路面土基顶面压应变、路表弯沉、层底拉应力的影响规律。依据不同底基层厚度及模量,优化分析不同土基模量和路床处理层模量下路床处理层的最佳厚度。最后,结合底基层与路床处理层材料单价,利用有限元设计程序对潮湿路段沥青路面结构进行优化设计,确定潮湿路段经济性最佳的沥青路面支撑结构组合。更多还原

【Abstract】 The structural parameters of pavement supporting system, composed by sub-grade, cushion and sub-base, have a direct influence on the stress condition and long-term performance of pavement. Because the high underground water table section silt sub-grade is always in moist condition, its poor bearing capacity can not satisfy the design requirement of sub-grade and pavement, the roadbed is necessarily to be consolidated to form a stable and strong supporting system with base layer. Therefore, based on the long-term performance of asphalt pavement, an integrated optimum design of pavement supporting structure in wet areas is proposed in this paper.Firstly based on the theory of unsaturated soil, the moisture content and resilience modulus of high underground water table section silt sub-grade are analyzed and forecasted via given models. The correlationship between compressive strain on top.of sub-grade soil and pavement deflection of normal asphalt pavement and durable asphalt pavement is established by finite-element analysis, and also the relationship between compressive strain on top of sub-grade soil and cumulative equivalent axle loads (the relationship between soil base top pressure strain design equation) on the basis of given relationship.The pavement supporting system parameters causing influence on stress condition and long term performance of normal asphalt pavement and long-life asphalt pavement is analyzed by finite-element method. And also analyze the influence on top roadbed compressed strain, the deflection on the surface and bottom layer tensile stress of asphalt pavement by sub-grade modulus, modulus and depth of sub-base and treated raodbed layer. The optimum thickness of treated roadbed layer is optimized in accordance with sub-base thickness and modulus under different conditions of sub-base and treated raodbed layer modulus. Finally, according to the reasonable modulus and the material prices of sub-base and treated roadbed layer, the optimum design of the asphalt pavement structure in wet areas is proceeded by finite element program, and then the most economical structure composition of asphalt pavement supporting is determined.更多还原