保温板在内蒙多年冻土区道路工程中的应用

根据博—牙高速沿线气象工程地质资料、观测资料、设计资料，借助有限元软件构建了路基温度场数值计算模型，着重对不同路基填筑高度条件下XPS板对温度场的影响进行了研究。研究发现:路基填筑高度的增加和XPS保温板的应用对冻土都起到了积极的保护作用，相同路堤填筑高度下，道路运营到第20年时，XPS保温板路基多年冻土温度比碎石路基降低了约0.19℃；XPS保温板的存在使得冻土上限上移更加明显，相同路基高度下，冻土上限平均抬升量约为1.23 m，在规范规定年限内，XPS保温板路基的冻土上限均位于换填碎石中；但XPS保温板的存在加剧了阴阳坡效应的发展，综合考虑，在本段落若采用碎石路堤建议路堤高度应保持在3 m以上；若采用XPS保温板路基，建议路堤高度不超过2 m。 

APPLICATION OF INSULATION BOARD IN ROAD ENGINEERING IN PERMAFROST REGIONS OF INNER MONGOLIA

Based on the meteorological engineering geological data, observation data and design data along the Bo-Ya expressway, a numerical calculation model of the roadbed temperature field was constructed by means of finite element software, and the influence of XPS insulation board on temperature field under different subgrade filling height was studied emphatically. The results show that, the increase of the subgrade height and the application of XPS insulation board both play a positive role in protecting permafrost. With the same embankment filling height, the temperature of permafrost of the subgrade with XPS insulation board reduces by about 0.19℃ than that of the subgrade with crushed rocks when the road runs to its twentieth years. XPS insulation board makes the upper limit of permafrost obviously raised, and the average uplift of the upper limit of permafrost is about 1.23 m under the same subgrade height. The upper limit of permafrost of subgrade with XPS insulation board is located in the replaced crushed rocks during the specified years of the designing code. However; the application of XPS insulation board aggravates the development of sunny-shady slope effect, the subgrade height with crushed rock should be kept above 3 m, and the subgrade height with XPS insulation board should be kept no more than 2 m.