保温处理措施在多年冻土区道路工程中的应用

Application of Thermal\|insulation Treatment to Roadway Engineering in Permafrost Regions

阐述了保温处理措施保护多年冻土的原理 ,认为保温材料下部地温年变幅的减小是保温处理措施保护多年冻土上限下降的主要效果 .青藏公路昆仑山越岭地段保温处理试验路段路基、路肩及天然地表下的地温观测资料证实 ,保温处理处理措施并不能改变因修筑路基而引起的路基吸热趋势 ,但是保温处理后浅层地温下降 ;地温年变幅明显减小 ,多年冻土上限比无保温处理路段高 .青藏铁路北麓河试验段保温处理试验路段半年的观测资料表明 ,保温层上下面温度存在巨大差异 ,充分体现了保温材料的热阻效应 ,可望大幅度减小保温材料下部地温的年变幅 ,起到保护或延缓多年冻土融化的效果 .

The principles of protecting permafrost with thermal\|insulating treatment are discussed in this. It is considered that the main effect of thermal\|insulation material is to decrease the annual changing range of ground temperature below the material. A test of thermal\|insulation treatment is performed in a section of the Qinghai-Tibetan highway, which is located around the pass of the Kunlun Mountains. The observed data of ground temperature under the roadbed, shoulders of the road and natural ground surface shows that the insulating treatment cannot change the endothermic trend due to the building of the highway, but can decrease both temperatures and annual temperature changing range in shallow ground. The permafrost table under the insulation\|treated roadbed is higher than that of non\|insulation sections. The decrease in annual temperature changing range shows a much great effect of thermal\|insulation, the dominant function of the thermal\|insulation treatment. In another test section, which is located in Beiluhe region of the Qinghai-Tibetan Railway under building, the observed data show a great temperature difference between the upper and bottom of insulation material. Thermal\|insulation effect is being sufficiently performed. It is expected that thermal\|insulation treatment greatly decrease the annual changing range of ground temperature and protect permafrost from thawing or delay the thawing trend.