沥青路面对高温多年冻土区块石路基自然对流降温效应的影响

发布时间：2018-01-19 03:28

本文关键词： 道路工程块石路基试验路监测高温多年冻土降温效应　出处：《中国公路学报》2015年12期 　论文类型：期刊论文

【摘要】：以青海共和至玉树公路K418+462处块石路基为研究对象,分析了沥青路面铺设前、后的块石层内地温、块石层底热流密度以及路基中孔地温变化过程,研究了沥青路面对块石层内自然对流降温效应的影响。结果表明:块石层内上下温差在路面铺设后明显降低,导致路面铺设后块石层中自然对流强度降低为路面铺设前的约40%;在沥青路面强吸热以及块石自然对流强度降低的影响下,冷季块石层峰值散热强度仅为路面铺设前的14%,同时造成暖季时路基吸热期延长约40d以及路基吸热峰值强度剧烈增加,最终表现为路基下伏多年冻土出现升温现象,冻土上限在路面铺设后下降约50cm。为增强块石路基在高温多年冻土区的适用性,建议尽量减少块石上部过渡层厚度,同时引入架空层来加强冷季时块石层内自然对流降温效应。
[Abstract]:Taking K418,462 block roadbed of Gong-Yushu highway in Qinghai as the research object, this paper analyzes the variation process of the interior temperature, the heat flux density and the ground temperature of the middle hole of the subgrade before and after the asphalt pavement paving. The effect of asphalt pavement on the natural convection cooling effect in the mass stone layer is studied. The results show that the temperature difference between the upper and lower layers decreases obviously after pavement laying. As a result, the natural convection intensity in the stone layer after pavement paving is reduced to about 40% before pavement laying. Under the influence of the strong heat absorption of asphalt pavement and the decrease of natural convection intensity of massive stone, the peak heat dissipation intensity of rock layer in cold season is only 14% of that before pavement laying. At the same time, the endothermic period of embankment during warm season is prolonged about 40 days, and the peak intensity of subgrade heat absorption is increased sharply, and finally the phenomenon of temperature rise appears in permafrost under subgrade. The upper limit of frozen soil is reduced by about 50 cm after pavement laying. In order to enhance the applicability of rock subgrade in high temperature permafrost region, it is suggested to reduce the thickness of upper transitional layer of block rock as far as possible. At the same time, the overhead layer is introduced to strengthen the natural convection cooling effect in the block rock layer during the cold season.
【作者单位】：中交第一公路勘察设计研究院有限公司多年冻土区公路建设与养护技术交通行业重点实验室;
【基金】：“十二五”国家科技支撑计划项目(2014BAG05B07;2014BAG05B03)
【分类号】：U416.168
【正文快照】： 0引言受多年冻土热融沉陷以及反复冻融循环影响[1-2],高温多年冻土地区路基极易出现差异融沉病害,严重影响路基稳定性和行车安全性。针对多年冻土层热融下沉问题,在寒区开展了大量保护多年冻土稳定性的特殊路基措施[3],其中块石路基作为一种在冻土地区广泛使用的路基工程措施,

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