热棒在多年冻土区堤防工程中的应用研究

为探究热棒在多年冻土区的降温性能，针对黑龙江干流多年冻土区选取试验区，并在试验区设置单热棒影响半径试验、双热棒无保温板试验与双热棒覆盖保温板试验。试验结果表明:热棒对多年冻土起到良好的保护作用，且从单桩热棒和群桩热棒对温度场的影响情况来看，其影响半径为２．５ｍ～３．０ｍ；群桩热棒影响下温度场变化会产生较为明显的叠加现象，而多年冻土多为连续分布，群桩热棒埋设作为一种较为常用的多年冻土降温措施，在埋设时应考虑结合基础宽度，尽量使叠加区域产生在靠近基础处；提出群桩热棒在多年冻土区水工建筑物地基中埋设的理想间距为３．６ｍ。同时，埋设群桩热棒并覆盖保温板的多年冻土保护措施可明显降低地温，有较为理想的工程效果。热棒主动降温技术能够有效抑制冻土区的冻融，从而防止融沉和冻胀，减轻冻土区水工建筑物的损害。

Thermosyphon Application in the Embankment Project in Permafrost Area

In order to explore the cooling performance of thermosyphons in permafrost regions,the experimental areas were selected in the permafrost regions along the main stream of Heilongjiang Province,and the influence radius test of single thermosyphon,the test without insulation board of double thermosyphons and the test of covering insulation board with double thermosyphons were set in the test area.The test results are as follows.From the influence of single thermosyphon and group thermosyphon on temperature field,the influence radius of thermosyphon is 2.5 m~3.0 m.The changes of temperature field under the influence of pile group thermosyphons produce obvious superposition phenomenon,and the permafrost is mostly continuous distribution.As a common cooling measure for permafrost,the embedded pile group thermosyphons should consider the width of the foundation to make the superposition area close to the foundation as far as possible;It is proposed that the ideal spacing of pile group thermosyphons embedded in the foundation of hydraulic structures in permafrost regions is 3.6 m.At the same time,the permafrost protection measures of burying pile group thermal rods and covering insulation board can significantly reduce the ground temperature.The active cooling technology of thermosyphon can effectively restrain the freezing and thawing of frozen soil area,at the same time prevent thawing settlement and frost heaving,and reduce the damage of hydraulic structures in frozen soil area.