碎石层反射率模型及其运用研究

阴阳坡效应对寒区道路工程建设质量和后期运营养护都有十分重要的影响,因此对边坡稳定技术的研究和创新成为当下的热点。在碎块石护坡表面喷涂浅色材料或高反射材料,将提高路基边坡的反辐射能力,从而可以大幅度减小地表接收的净辐射和增强块碎石层的冷却效果。通过建立碎石粗糙表面能量吸收模型,推导出碎石粗糙表面的宏观反射率R与微观反射率r之间的关系。借助于图像处理分析方法,准确分析碎石和孔洞区域的面积,据此估算碎石层的反射率,并利用实测数据验证模型的可靠性。对模型参数进行分析发现:降低块石表面粗糙度和近地面空隙度有利于提高整个碎石层的反射率;碎石表面的粗糙度抑制了宏观反射率R的提高;涂料的最佳选择要根据碎石层粗糙程度决定,建议选择涂料反射率在0.4~0.6为宜。

Reflectivity of Crushed Rock Layer: Model and Its Application

The sunny and shady slope effect exerts significant impact on the construction quality and operation and maintenance of road engineering in cold regions. Coating the embankment surface with materials of light color or high reflectivity will improve the anti-radiation ability of subgrade slope, intensify the cooling effect of crushed rock layer, and remarkably reduce the received net radiation. An energy absorption model for crushed rock rough surface is established to deduce the relationship between the macro-reflectivity R and the micro-reflectivity r on the surface of rough crushed rock. In association with image processing, the reflectivity of crushed rock layer is estimated by obtaining the area of crushed rock and cavities. Furthermore, the reliability of the established model is verified by measured data. Analysis on model parameters reveals that reducing the roughness of rock surface and the ground clearance degree are conducive to improving the reflectivity of the whole crushed rock layer. Roughness of crushed rock severely inhibits the improvement of macro-reflectivity R. In addition, the selection of coating material should be depended on the roughness, and we recommend the reflectivity of coating between 0.4-0.6.