【作者】 刘伟；

【导师】 魏静；

【作者基本信息】 北京交通大学 ， 道路与铁道工程， 2014， 硕士

【摘要】 214国道是在青藏高原修建的第一条黑色宽幅高速公路,沿线经过高温不稳定多年冻土区,存在较严重的冻土退化趋势,需要开展冻土路基修筑后温度及变形趋势状况的研究。本文根据现场实测气象资料,考虑全球气温升高的影响,分析了该高等级公路典型路基断面的温度场及变形,进而研究了不同路面性状、不同路基宽度对路基温度场及变形的影响,得出如下结论：1、综合分析了1990～2008年,青藏高原典型地段清水河、玛多、玉树的年均气温变化情况,其温度分别升高0.48℃、1.37℃、1.91℃,统计数据趋势表明随海拔高度增加气温变暖的速率减缓,此结论为建立线性土工建筑物与大气热质交换机理模型奠定了基础。2、考虑高速公路上的车辆荷载,建立有限元模型,通过对214国道进行温度场及变形情况的分析表明,温度在典型黑色宽幅路基中的传播具有明显的滞后性,滞后约4个月,并随着路基高度的增加温度延迟现象更加明显。路基内部竖向位移变化幅度最大,位移变化规律与温度场分析中融土核的变化规律吻合,冻融循环是引起路基竖向位移的主要原因。3、沥青路面路基温度明显高于水泥路面路基温度,且水泥路面路基下融土核比沥青路面路基下融土核提前约3个月消失。水泥路面路基的竖向位移比沥青路面路基的竖向位移小2-3mm左右。窄幅路基的融土核比宽幅路基的融土核提早一个月消失。全年除4、5月份,窄幅路基的竖向位移均小于宽幅路基,两者竖向位移相差最大处发生在12月,约为5.53mm。研究结果显示,黑色宽幅路基同水泥路面路基及窄幅路基相比,吸热及储热能力强,路基竖向位移大；水泥路面路基较窄幅路基对多年冻土的保护作用更加明显。更多还原

【Abstract】 G214is an asphalt road with the wide embankment, and it is also the first expressway built on Qinghai-Tibet Plateau. The ground temperature of permafrost is somewhat warmer and this kind of permafrost belongs to high-temperature regions and degradation seriously. Considering the conditions of global warming, based on the temperature field measurement data, the temperature field and deformation of this particular highway is discussed in this thesis. How the temperature field and deformation conditions are affected by the different pavement and different embankment width is analyzed and compared. The conclusions are as follows:1、The average annual temperature in Qingshui River、Maduo、Yushu have increased0.48℃、1.37℃、1.91℃, from1990to2008. And according the altitude increases the rate of warming is slowing.2、Consider the vehicle load on the highway, and build the finite element model found that, temperature spread in the embankment with a lag of about four months compared with surface. Vertical displacement of embankment internal was found the biggest and the displacement variation law was in accordance with the variation of melt soil cores. It shows that the freeze-thaw cycle is the main reason for vertical displacement.3、Temperature of asphalt pavement subgrade is significantly higher than the temperature of the cement pavement subgrade, and the melt soil cores in the cement pavement subgrade disappeared3months earlier than those in asphalt pavement subgrade. The vertical deformation of concrete pavement is2～3mm less than that of asphalt pavement. The melt soil cores in the normal embankment disappeared1month earlier than those in wide embankment. The displacement of normal embankment is always less than that of wide embankment except April and May. The biggest difference between the two vertical displacements occurred in December at about5.53mm.Compare with the cement pavement and the normal embankment, the asphalt road with the wide embankment absorb more beat and produce more displacement, the cement pavement subgrade is better to protect the permafrost than the normal subgrade.更多还原