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为了研究热棒在青藏公路多年冻土区的应用效果,基于楚玛尔河试验监测场地8年的地温观测数据,以水平温度梯度为指标,分析了不同时期热棒的有效半径。为了提高热棒的调控效果,拓展热棒的使用范围,满足宽幅路基强吸热的使用要求,依托北麓河与安多2个试验监测场地,分析了热棒-XPS板路基与热棒-片块石路基地温监测数据。分析结果表明:热棒工作1年后的有效半径约为2.3m,此后,随着热棒工作时间的增加,热棒影响范围逐渐增大;在热棒工作的前5年,地温降幅明显,周围土体地温降幅都基本维持在0.5℃以上,之后每年降温较小,这主要是由于外界环境温度升高,气温与地温的温差逐渐减小,热棒工作的动力逐渐衰减引起的;在热棒工作的8年中,由于热棒的持续制冷作用,热棒路基的人为上限基本不变,而普通路基同时期人为上限最大降低约为80cm;热棒-XPS板路基从6月份开始,XPS板上下温差不断增大,最大温差约为17℃,有效阻隔了暖季大量热量向板下传递;热棒-片块石路基通过2年的调控作用,地温最大降幅为0.51℃。
In order to study the application effects of hot rods in the permafrost regions of Qinghai-Tibet Highway, the effective temperature of hot rods in different periods was analyzed based on the 8-year geothermal observation data from the monitoring site of the Chumar River. The horizontal temperature gradient was used as an index. In order to improve the control effect of hot rods and expand the use range of hot rods to meet the requirements of strong heat absorption of wide subgrade, relying on the two experimental monitoring sites of Beiluhe and Anduo, the hot rod-XPS plate subgrade and hot rod - Block stone road base temperature monitoring data. The results show that the effective radius of the hot rod after one year is about 2.3m, and then the influence range of the hot rod increases with the increase of the working time of the hot rod. In the first five years of the hot rod’s work, the temperature drop obviously, The temperature drop around the soil is basically maintained at above 0.5 ℃, and then a small annual cooling, mainly due to the external environment temperature, temperature and ground temperature gradually decreased, the work of the hot rod power gradually decay caused; in the heat During the eight years of stick work, due to the continuous cooling effect of the hot rod, the artificial upper limit of the hot rod subgrade remained unchanged, while the maximum reduction of the artificial upper limit of the common subgrade during the same period was about 80 cm. The hot rod-XPS board embankment started from June and XPS The maximum temperature difference is about 17 ℃, which effectively blocks the large amount of heat transferred to the plate during the warm season. The hot rod-block stone roadbed has the maximum decrease of 0.51 ℃ after 2 years of regulation.