柴木铁路热棒试验断面冷却效果研究

Study on Cooling Effect of Thermal Pipes for Permafrost Embankment of Chaidaer-Muli Railway

柴达尔至木里铁路是青海省地方铁路,全线均有多年冻土分布,依据青藏铁路热棒应用的成功经验,其部分路段施行了热棒冷却措施。不同于青藏铁路沿线气候和冻土条件,柴木铁路热棒应用效果有待于检验。设置三个试验断面,分析了气温条件,比较研究了热棒和无热棒路基地温变化的不同,结果表明:(1)柴木铁路大风频繁、气温低、温差大的气候条件有利于热棒的应用;(2)无热棒断面路基地面深度3 m以下地温波动较小,长期稳定在-1℃附近;(3)在第二个冻融周期的冬季,热棒能够有效地降低路基温度;(4)热棒断面路基第二年的冬季降温效果非常显著,冻土上限最大抬升了1.5 m。热棒冷却措施能够保障柴木铁路多年冻土路基稳定,为铁路的正常运营提供保证。

Chaidaer-Muli Railway is a local railway in Qinghai Province, along which the permafrost distributed. Based on experience of cooling embankment by thermal pipes used along Qinghai-Tibet railway,this technology is now used along Chaidaer-Muli Railway. Three experimental sections were designed to investigate cooling effect by analyzing atmosphere and differences of ground temperature between thermal pipe embankment and non-thermal-pipe embankment,the results showed that,（ 1） the climate in Chaidaer-Muli region with frequent strong winds,low air temperatures and large temperature range are in favor of application of thermal pipes;（ 2） the ground temperatures at depth below 3m in non-thermal pipe section vary in a narrow range,stabilizing at about- 1℃ in long-term;（ 3） the permafrost embankment temperature can be lowered effectively by thermal pipe in winter of the second freezethaw cycle;（ 4） the ground temperature of thermal pipe embankment is obviously lowered in the next winter compared to that of non-thermal pipe section,and permafrost table is raised about 1.5m. Application of thermal pipe along Chaidaer-Muli railway would guarantee stability of permafrost embankment and operation of train in the future.