多年冻土区路堑边坡防护试验研究

Experimental Study on Protection of Cutting Slope in Permafrost Region

研究目的:目前,多年冻土区路堑边坡防护方面开展的试验研究较少,缺乏设计、施工和应用效果等方面的研究成果。基于青藏铁路北麓河试验段柔性护坡试验工程的地温和变形观测资料,分析了泡沫玻璃护坡和草皮护坡下的地温发展变化规律和边坡纵向变形过程,阐述了两种柔性护坡防护工程的应用效果,希望为多年冻土区道路工程边坡防护设计、施工提供科学依据。研究结论:泡沫玻璃板短期内具有较好的保温效果,可以减小季节融化深度,有利于边坡的稳定。但泡沫玻璃护坡段冻结期发生了较明显的冻胀变形,并导致泡沫玻璃在外力下的破碎和断裂。考虑到其易风化,抗变形能力和适应性较差,该种泡沫玻璃不宜在多年冻土区路堑边坡防护工程中推广应用。草皮护坡段下的季节融化深度较大,但草皮护坡整体上大部分比较平整,变形较小,其变形适应性较好,可能是比较适宜在多年冻土区路堑工程中应用的边坡防护形式之一。

Research purposes： Now there is little experimental study being done on protection of cutting slope in permafrost region, thus, there is little study result of it. Based on the observation data on the ground temperature and the deformation of experimental flexible revetment at Beiluhe field site on the Qinghai -Tibet railway, the development law of ground temperature and the longitudinal deformation process of slope under the effects of glass foam revetment and the sward revetment are analyzed and the applicable effects of them are presented for providing the basis for the design and construction of revetment in permafrost region. Research conclusions： The experimental study results show that the glass foam revetment is better than the sward revetment in insulated during the experimental period, which can reduce the seasonable thawing depth and benefit the stability of the slope. However, the obvious frozen deformation can appear to the glass form revetment in frozen period, resulting in its breaking and crack under external force. As the glass foam is easy to be weathered and weak in non - deformability and adaptability, it is unsuitable for being used in permafrost region. As the thawing depth of sward revetment is deeper than that of the glass foam revetment and most parts of sward revetment are flat with small deformation and good adaptability, the sward revetment is suitable for being used in permafrost region.