基于固-液两相流的透水混凝土路面孔隙堵塞细观机理研究

Pervious concrete pavements have good drainage and noise reduction capabilities, and also have the ecological function of regulating surface temperature and humidity; they have been widely used in many countries. However, drainage capacity will be greatly decreased, once the pores clogged in permeable pavements. To reveal the meso-mechanism of sediment clogging in the pores of the pervious pavement under surface runoff and its mechanical behaviors, optimize pervious pavement structural design and conservation methods, reduce maintenance costs, the project uses experimental and flow-solid coupling numerical methods to study the sand clogging issues of pervious pavements. By establishing the model of three-dimensional surface runoff - pervious pavement - sediments system, to study the interaction inside the solid - liquid two-phase system, optimize the model structure and parameters. By experimental and numerical methods to study the mechanical properties of the water - sediment interaction and effects of infiltration to the movements of sediment particles; to reveal the mechanism of sediment entering, moving through, leaving and clogging in the pores; to determine the effects of aggregate gradation and size, aggregate - cement ratio, porosity and pore size to the anti-clogging ability of the pervious pavement. Based on the study of these key scientific issues, it will provide the scientific and effective basis of the design and construction programs and parameter selection, maintenance and repair measures of pervious pavement, and it will also promote the disease research of pervious pavements.

透水混凝土路面具有良好的排水和降噪能力，并有调节地表温湿度等生态功能，已被许多国家广泛应用，然而透水路面的孔隙一旦堵塞,其排水能力将大大下降。为揭示泥沙在地表径流的作用下堵塞透水路面孔隙的细观机理及其力学特性，优化透水路面结构设计与养护方法，降低养护成本，本课题运用试验与流-固耦合数值方法对透水路面泥沙堵塞问题展开研究。通过建立三维地表径流-透水路面-运动泥沙颗粒系统模型，研究固-液两相系统中各部分相互作用影响规律，优化模型结构以及参数。通过试验和数值方法研究水流-泥沙相互作用力学特性以及水流下渗对泥沙颗粒运动的影响；揭示泥沙进入、通过、离开以及堵塞孔隙的机理；确定透水路面集料级配与粒径、集灰比、孔隙率与孔径尺寸等对透水性路面抗堵塞能力的影响。通过以上关键科学问题的研究，为透水路面设计施工方案和参数的选取、养护维修措施的制定提供科学有效的依据，推动透水路面病害学领域的研究和发展。

透水混凝土路面具有良好的排水和降噪能力，并有调节地表温湿度等生态功能，已被许多国家广泛应用，我国正在开展的海绵城市建设中也大量应用了透水路面以使雨水下渗，然而透水路面的孔隙一旦堵塞,其排水能力将大大下降。为揭示泥沙在地表径流的作用下堵塞透水路面孔隙的细观机理及其力学特性，优化透水路面结构设计与养护方法，降低养护成本，本课题运用试验与流-固耦合数值方法对透水路面泥沙堵塞问题展开研究。通过建立三维数值模型研究了带自由表面的地表径流携带的大量泥沙颗粒在透水性路面附近及孔隙内复杂的运动现象，明确了水流-泥沙相互作用力学特性以及水流下渗对泥沙颗粒运动的影响；揭示泥沙造成孔隙堵塞的机理，确定了孔隙堵塞的三个阶段；对比了透水路面集料级配与粒径、孔隙率与流速等对透水性路面发生堵塞的影响；围绕地表径流、透水路面、运动泥沙颗粒三者之间的相互作用开展了系统而深入的研究，从而提出导致透水路面堵塞的各因素对路面渗透性影响的快速堵塞模型。通过以上关键科学问题的研究，为透水性路面设计施工方案和参数的选取、养护维修措施的制定提供科学有效的依据，推动透水混凝土路面病害学领域的研究和发展。