水损害是多雨地区路面的主要病害之一，合理的排水系统是降低水损害的重要手段。针对目前我国路面排水基层设计理论基础存在的不足，申请人前期研究探索了非饱和渗流对排水基层排水过程的重要影响。作为前期研究的延续和拓展，本课题拟以路面排水基层的设计理论和方法为切入点，基于路面病害调查分析并结合路面渗水试验，建立路表水渗入率计算的理论和数值仿真模型，获得路表水渗入率估算表达式，为排水基层设计提供依据；通过室内试验获得排水材料非饱和渗流性质与力学性能之间的关系，为建立渗流模型以及理论分析提供基础；基于非饱和渗流理论建立排水基层稳态和瞬态渗流模型，获得排水基层孔隙水的渗流特征，并与室内模型试验和数值模拟进行对比验证；通过优化材料和结构参数的组合关系提出排水基层"厚度-强度-渗透性"平衡设计方法以及排水基层排水效率的评价方法。本项目成果将为拓展和完善国内外路面内部结构排水系统的设计和评价提供有益的理论参考。

The water-induced damage is one of the main diseases with respect to the pavement of highway in high-rainfall area, and the appropriate drainage system is a significant measurement to reduce the water-induced damage.Currently,there are shortages in terms of the theory foundation in the drainage layer design of highway. The applicant's previous researches investigated the capillary effect on the flow in drainage layer of highway, and it demonstrated that the unsaturated flow should not be neglected in the drainage layer design. Accordingly, as a continued and extended study, the theory and method of design for the drainage layer in highway pavement is selected as the breakthrough point of this research. Based on the investigation analysis of pavement diseases, water penetration test and percolation theory, the simulation model and method will be established and presented to determine the quantity of inflow which offer the reference to the material selection and structure design of the draiange layer. Futher，the relationship between the unsaturated hydraulic properties and mechanical performance of the drainage materials will be obtained through laboratory tests, which is the foundation for flow model establishment and theoretical analysis. Then, the flow models with respected to steady-state and transient flow in the drainage layer will be developed and the solutions of water table distribution in the drainage layer will be obtained and validated through the numerical as well as laboratory methods. Furthermore, based on the numerical simulation, the test and the theoretical analysis results, the balanced design method in terms of "thickness-strength-permeability" and the evaluation method will be presented through optimizing the combinational relationships of the parameters of the drainage material and structure of the drainage layer. The theory and method with respected to drainage layer design of highway pavement will offer the beneficial reference to extend and improve the efficiency of drainage design and evaluation related to structure drainage system of highway.