青藏铁路热棒路基结构形式及工作状态分析

Structure Type and work State Study on Heat Pipe Subgrade of Qinghai-Tibet Railway

热棒是一种有效的主动降温工程措施.由于施工简便,制冷效果显著,在青藏铁路多年冻土路基工程中得到广泛应用,并且可以做为多年冻土路基工程病害处理的重要措施.为研究热棒路基的应用结构形式,在青藏铁路清水河试验段和安多试验段对各种路基结构形式下热棒的工作状态进行了观测研究.研究表明,热棒在青藏高原多年冻土区使用的每年有效制冷工作时间长达7个月,冷却半径大于2.5 m.斜插方式布设热棒路基对路基体下土层的制冷效果更好,并且有利于消除由于“驼峰”效应而引起的路基纵向裂缝,是一种优于直插式热棒的路基结构形式.

Heat pipe, as an effective means to actively cooling subgrade, is widely used in Qinghai-Tibet Railway. It is very easy to be constructed and is considered as an important method to protect subgrade from frost damage. The experiment of heat pipe subgrades has been constructed in Qingshuihe and Anduo in order to research the cooling ability and effectivity . The observation results show that the cooling work period of the heat pipe is about 7 months and the cooling radius is more than 2.5 m. The cooling effectivity of heat pipe slanting inserted into subgrade is better than that one vertically insered into subgrade. The heat pipe slanting inserted into subgrade is better structure subgrade to eliminate the concave shape of permafrost table and protect from cracks along the center line of subgrde.