青藏铁路冻土路基热棒应用效果试验研究

通过青藏铁路沿线典型冻土路段热棒试验路基和对比路基的地温及变形现场监测,研究热棒对多年冻土路基的保护效果。通过对埋置在正线试验路基左侧不同规格热棒周围地温的监测,研究热棒构造对路基降温效果的影响。试验结果表明,热棒显著抬升路基下部多年冻土的天然上限,其最大平均抬升值达1.66 m;斜插方式埋置热棒能使最大融化深度曲线更快地趋于平缓,达到对路基下部多年冻土的整体保护;热棒路基的累计变形远小于未设置热棒的对比路基;热棒的产冷功率越大,其降温效果越好,降温范围也越大。

Test Study on the Application Effect of the Thermal Pipes on the Roadbed in the Permafrost Region along Qinghai-Tibet Railway

By monitoring the ground temperature and the deformation of the thermal pipes test roadbed and the contrastive roadbed of typical permafrost section along Qinghai-Tibet Railway on the spot,the protective effect of the thermal pipes on permafrost embankment is studied.Meanwhile,through monitoring the ground temperatures around the thermal pipes with different diameters and lengths of thermal pipes buried on the left of the main test embankment,the influence of thermal pipe structure on the cooling effect of thermal pipes is investigated.The field test results show that thermal pipes can remarkably raise the natural upper limit of permafrost beneath the railway roadbed,whose maximum average value rises up to 1.66 m.Inserting thermal pipes into roadbed slantingly can more quickly enable the maximum melting depth curve to be steady and smooth,which can wholly protect the permafrost beneath the railway roadbed.The accumulative deformation of thermal pipes embankment is far less than that of the contrastive embankment without thermal pipes.The higher the cooling power of thermal pipes is,the more effective its cooling effect and the greater the range of its temperature falling will be.