摘要
针对青藏高原多风的特点及其气温和地质条件,在考虑全球变暖的条件下,研究青藏铁路开放块碎石夹层路基和开放块碎石护坡路基的速度场及其在未来50年的温度场变化特征。结果表明,在外界风的作用下,两种块碎石路基的道砟层和块碎石层内的对流换热方式以强迫对流为主;在年平均气温为-4.0℃,考虑未来50年青藏高原气温升高2.2℃条件下,这两种路基结构均能不同程度地抵消气候变暖和铁路建设所带来的负面影响,对其下部多年冻土起积极保护作用,但开放块碎石夹层路基的降温效果好于开放块碎石护坡路基,而且还发现在铁路运营50年后开放块碎石护坡路基内部将出现终年融化夹层,这一问题应引起设计与施工部门的重视,以采取相应的措施来维护这种冻土路基的多年稳定。
Based on the wind features and temperature and geology conditions on the Qinghai-Tibet Plateau studies were made to the velocity and temperature characteristics of the open crushed-stone interlayer embankment and open crushed-stone revetment embankment in the coming 50 years under a global warming condition are studied. The results show that, due to the influence of the external wind, the convective heat transfer in the two embankment structures mainly relies on the forced convection. Even if the temperature rises by 2.2℃ in the coming 50 years, both embankments can counteract to a certain extent, the influences by climatic warming and railway construction, thus providing a good cooling effect on the underlying permafrost if the em- bankments are constructed in the regions where the present mean annual temperature is --4.0℃. The cooling effect of the open crushed-stone interlayer embankment is better than that of the open crushed-stone revetment embankment. Furthermore, it is found that a residual thawed layer will occur in the open crushed-stone revet- ment embankment in 50 years after the embankment was constructed. Attention should be paid to it this problem and corresponding measures be taken so as to ensure the stability of permafrost embankments.
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2007年第5期73-78,共6页
Journal of the China Railway Society
基金
国家自然科学基金资助项目(40601023)
国家杰出青年科学基金资助项目(40225001)
中国科学院知识创新工程重要方向项目(KZCX3-SW-351)
关键词
开放边界
块碎石类路基
速度场
温度场
多年冻土
青藏铁路
open boundary
crushed-stone embankment
velocity
temperature
permafrost
Qinghai-Tibet Railway
