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。
Abstract
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.
关键词
碎石层 /
阴阳坡效应 /
多重反射 /
反射率 /
粗糙度 /
图像处理 /
多年冻土
Key words
crushed rock layer /
sunny and shady slope effect /
multiple reflectance /
reflectivity /
roughness /
image processing /
permafrost
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 王可丽，程国栋. 青藏铁路沿线地表和路基表面热力学模式(I):物理过程与实验方案[J] .冰川冻土, 2002，24(6):760-764.
[2] WEI Ma, WEN Zhi, SHENG Yu,et al. Remedying Embankment Thaw Settlement in a Warm Permafrost Region with Thermosyphons and Crushed Rock Revetment[J].Canadian Geotechnical Journal, 2012, 49(9): 1005-1014.
[3] CHOU Y L, SHENG Y, WEI Z M,et al. Calculation of Temperature Differences Between the Sunny Slopes and the Shady Slopes along Railways in Permafrost Regions on QinghaiTibet Plateau[J].Cold Regions Science and Technology, 2008, 53(3): 346-354.
[4] CHOU Y L, SHENG Y, MA W. Study on the Effect of the Thermal Regime Differences in Roadbed Slopes on Their Thawing Features in Permafrost Regions of QinghaiTibetan Plateau[J].Cold Regions Science and Technology, 2008, 53(3): 334-345.
[5] 吴青柏，赵世运，马巍，等. 青藏铁路块石路基结构的冷却效果监测分析[J] .岩土工程学报, 2005，27 (12):1386-1390.
[6] 张明义，赖远明，高志华，等. 开放条件下粒径对块石和碎石护坡降温效果影响的试验研究[J] .岩土工程学报, 2006，28(11)：1986-1990.
[7] LAI Y, ZHANG L, ZHANG S,et al. Cooling Effect of Rippedstone Embankments on QingTibet Railway under Climatic Warming[J].Chinese Science Bulletin, 2003, 48(6): 598-604.
[8] SUN Z, MA W, LI Y. In situ Test on Cooling Effectiveness of Air Convection Embankment with Crushed Rock Slope Protection in Permafrost Regions[J].Journal of Cold Regions Engineering，2005, 19(2): 38-51.
[9] 喻文兵，赖远明，张学富，等. 多年冻土区道碴、通风管结构铁路路基室内试验研究[J].岩土工程学报, 2003, 25(4): 436-440.
[10] 喻文兵，程国栋，牛富俊.自动温控通风路基应用效果分析[J] .岩石力学与工程学报,2004，23(24)：4421-4428.
[11] 潘卫东,赵肃菖,徐伟泽,等. 热棒技术加强高原冻土区路基热稳定性的应用研究[J].冰川冻土, 2003,25(4):433-438.
[12] GUNTOR N A A,DIN M F M,PONRAJ M,et al. Thermal Performance of Developed Coating Material as Cool Pavement Material for Tropical Regions[J].Journal of Materials in Civil Engineering, 2014, 26(4): 755-760.
[13] 吕振北,段延红,韩之栋,等. 降低沥青混凝土路面储热量措施对比研究[J] .公路, 2012, (6): 128-131.
[14] POMERANTZ M,AKBARI H. Cooler Paving Materials for Heat-island Mitigation[C] ∥Proceedings of the 1998 ACEEE Summer Study on Energy Efficiency in Building. ACEEE, California, August 23-28, 1998: 135-146.
[15] 冯文杰,马 巍. 青藏铁路遮阳板措施应用效果观测研究[J].冰川冻土,2006, 28(1): 128-131.
[16] QIN Y H,TAN K H,LIANG J,et al. Shading Boards with Smaller Lower-surface Thermal Emissivity Perform Better Cooling Effect[J].Cold Regions Science and Technology,2015,120:30-34.
[17] 苏亚欣,范晓伟. 传热学[M].武汉:华中科技大学出版社,2009:187-188.
[18] QIN Y H,TAN K H,LIANG J,et al.Experimental Study on the Solar Reflectance of Crushed Rock Layer with Different Sizes[J] .Environmental Earth Sciences,2016,75: 817.
[19] 徐新阳, 康 雁, 陈 旭,等. 分形漫步[M].刘 丹,译. 沈阳:东北大学出版社,1994:226-230.
[20] SUN B X, XU X Z, LAI Y M, et al. Evaluation of Fractured Rock Layer Heights in Ballast Railway Embankment Based on Cooling Effect of Natural Convection in Cold Regions[J].Cold Regions Science and Technology, 2005, 42(2): 120-144.
[21] QIN Y H. Urban Canyon Albedo and Its Implication on the Use of Reflective Cool Pavements[J].Energy and Buildings, 2015, 96: 86-94.
基金
国家自然科学基金项目(51508114,41561015);广西自然科学基金项目(2015GXNSFBA139212)
PDF(2572 KB)
