Engineering Effects of the Sunshine-shield Roadbed of the Qinghai-Tibet Railway in Permafrost Regions
Engineering Effects of the Sunshine-shield Roadbed of the Qinghai-Tibet Railway in Permafrost Regions
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发表时间：
2010
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通讯作者：
L. Hua
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作者：
L. Hua
引起气温和地温升高的主要因素是太阳辐射。对地表进行太阳辐射屏蔽可以有效地降低地温。根据青藏铁路多年冻土区日光盾构路基现场测试结果，监测期间盾构内年平均气温比盾构外低0.6 ℃。在原始条件下，距地面0.1 ~ 0.3m高度范围内的平均气温比1.0m高度范围内的平均气温高1.0 ℃。而在护罩内，温度相差只有0.3 ℃。暖季一天中14：00时，防护罩内气温比防护罩外低6.0 ℃。14：00时0.1m高度的MAAT，屏蔽内比屏蔽外低4.2 ℃。在1.5m高度上的温差为2.1 ℃。由于盾构的作用，盾构下地温降低，人工冻土上限升高，最高达1.0m。气温和地温变化均表明遮阳板能有效地保护下伏冻土。
The main factor causing rise of air temperature and ground temperature is solar radiation. To shield ground surface from solar radiation can effectively lower ground temperature. According to the field testing results of sunshine-shield roadbed in the Qinghai-Tibet Railway in permafrost regions,the mean annual air temperature (MAAT) inside the shield was 0.6 ℃ lower than that outside the shield during the monitored period. Under the original conditions,the MAAT within a height range from 0.1 to 0.3 m above ground surface was 1.0 ℃ higher than that of 1.0 m. However,the difference was only 0.3 ℃ inside the shield. The air temperature at 14:00 in a day during the warm season inside the shield was 6.0 ℃ lower than that outside the shield. The MAAT at 14:00 at 0.1 m height inside the shield was 4.2 ℃ lower than that outside the shield. And the difference at the height of 1.5 m was 2.1 ℃. Owing to the effect of the shield,the ground temperature under the shield decreased and the artificial permafrost table rose,with a maximum of 1.0 m. Both the air temperature and the ground temperature changes indicated that the sunshine-shield can effectively protect the underlying permafrost.