多冻土地区块石气冷拓宽路基差异融沉处治效果分析  

Analysis of Differential Thaw Settlement Treatment Effect of Widened Crashed Rock Embankment in Permafrost Regions

作　　者：李朋飞[1] 袁堃[2] 牛富俊[3] 穆柯[2] 

机构地区：[1]长安大学,陕西西安710064 [2]中交第一公路勘察设计研究院有限公司,陕西西安710075 [3]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000

出　　处：《公路交通科技》2015年第7期47-54,共8页Journal of Highway and Transportation Research and Development

基　　金：国家科技支撑计划(2014BAG05B07;2014BAG05B03);国家重点基础研究发展计划(八六三计划)项目(2012CB026106);中交集团科技研发项目(2011-ZJKJ-16)

摘　　要：为了减少多年冻土拓宽路基差异融沉,提出块石气冷拓宽路基处治方案,在路基下伏多年冻土横向差异退化的背景下,以多孔介质自然对流换热理论为基础,建立了块石拓宽气冷路基数值计算模型,对利用旧路拓宽,以及翻挖旧路并原位新建块石气冷拓宽路基两种不同建设模式进行了数值模拟,分析了块石层内空气对流特征、多年冻土层长期热稳定性变化过程以及新旧地基冻土层差异融沉控制效果。结果表明:块石拓宽路基在提高阳坡路肩下多年冻土层热稳定性方面起到了积极作用,拓宽路肩下多年冻土层在新建黑色沥青路面强吸热作用下未出现明显退化,块石拓宽路基在消除阴阳坡冻土差异退化方面效果明显。在既有旧路病害严重路段,需要对旧路地基和拓宽地基起到双重调控作用,适宜采用翻挖旧路并原位新建块石气冷拓宽路基,对新旧路基差异融沉可以起到更好的控制效果。In order to reduce the differential thaw settlement of widened embankment in permafrost regions, a treatment scheme of widening crashed rock embankment is put forward. Considering the background of permafrost horizontal differential degradation condition, a numerical model of widening crashed rock embankment is established based on the theory of natural convection heat transfer in porous media. Two construction modes are simulated, one is old embankment widening, the other is excavating old embankment then building new widened crashed rock embankment. The air convection feature, long-term thermal stability of permafrost, and differential thaw settlement control effect between new and old embankments in crashed rock are analyzed. The result shows that （1） the widened crashed rock embankment plays a positive role in enhancing the thermal stability of permafrost in sunny slope, the permafrost beneath the widened road shoulder does not appear notable degradation under the strong endothermic of black asphalt pavement, and permafrost differential degradation between sunny and shady slopes is reduced bv widening crashed rock embankment; （2） in the serious road disease section, it would be hetter to excavating old embankment then ta,ilding new widened crashed rock embankment that is able to play dual function to oht embankment and widened embankment respectively, thus a better differential thaw settlement control effect could be obtained.

关 键 词：道路工程 块石气冷拓宽路基 数值模拟 多年冻土 热稳定性 

分 类 号：U416.1[交通运输工程—道路与铁道工程]