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考虑多年冻土中水的相变,采用有限元进行热管保护多年冻土路基效果的三维数值分析。分析结果表明,热管能大幅度降低路基土体的温度,提升路基冻土上限,增大路基抵抗外界温度变化的能力,保证路基的长期稳定。考虑路基工程所在冻土区段气候和冻土条件,研究热管的有效影响范围,得出结论:热管的有效冷却半径为1 7m左右;在年平均气温为-5 2℃,冻土年平均地温为-1 0℃以上的高温冻土区,热管埋设间距宜取2 8～3 3m,可抬升路基冻土上限0 6～0 8m;在年平均气温为-6 3℃,冻土年平均地温低于-2 0℃的低温冻土区,热管埋设间距可加大到3 3～3 8m,路基冻土上限可抬升0 8～1 2m。
Taking the phase change of water in permafrost into consideration, the three-dimensional numerical analysis of the effect of permafrost embankment by finite element heat pipe is taken. The analysis results show that the heat pipe can greatly reduce the temperature of subgrade soils, increase the upper limit of permafrost and increase the ability of embankment to resist external temperature changes, and ensure the long-term stability of subgrade. Considering the conditions of the permafrost zone and the permafrost zone of the subgrade project, the effective range of the heat pipe is studied. The conclusion is that the effective cooling radius of the heat pipe is about 17 m and the average annual temperature of the permafrost is -5 2 ℃. For the high-temperature permafrost areas above -1 0 ℃, the spacing of the heat pipe should be 2 8 ~ 3 3m, and the upper limit of permafrost can be raised 0 6 ~ 0 8m. At the annual mean temperature of -6 3 ℃, Below -20 ℃ permafrost areas, heat pipe buried spacing can be increased to 33 ~ 38m, the upper limit of permafrost can be raised 0 8 ~ 1 2m.