Permafrost

with their subsequent freezing and other actions.
Effective monitoring of a status of the protecting dam, carried out by experts of Polar
branch GMK "Nornikel", allows to accept in an operative mode actions necessary engineering -
cryopedology on increase of stability of hydraulic engineering constructions of region.
Key words: Hydraulic engineering constructions, frozen ground
Investigation of Laboratory Experiment on Cooling Effect of Embankment
with Perforated Ventilation Pipe
46
Qi Liu, Bin-xiang Sun, Xiao-zu Xu
(Department of Civil Engineering, Shaoxing College of Arts and Sciences, Shaoxing 312000, China)
Abstract: A technique of laboratory experiment modeling for the cooling mechanism in
perforated ventilation pipe embankments was introduced. Various ventilated-embankment
samples with dimensions of 100×60×100cm under cyclically fluctuating upper-surface
temperature were studied experimentally. The analysis shows that the ventilated embankment
with perforated ventilation pipe can enhance the cooling effectiveness of the embankment base.
The cooling effect of perforated ventilation pipe embankment only ventilating during negative
temperature is strongest. Temperature change amplitudes and distribution ranges of negative
temperature in the vicinity of air inlet of ventilation pipe are larger than that in the vicinity of
air outlet of ventilation pipe. This is a direct consequence of unsymmetrical temperature
distribution along a wind direction parallel to the ventilation pipe. Under the same cyclically
fluctuating temperatures, the cooling effects of ventilation pipe embankment are increased with
increasing wind velocity in the ventilation pipe.
Key words: permafrost; ventilation pipe embankment; cooling effect; self-windward vent;
perforated ventilation pipe
Analysis of Cooling Effect for Block-Stone Embankment of
Qinghai-Xizang Railway
Qingbai Wu 1 , Zijian Lu 1 , Wei Ma 1 , Luxin Zhang 1,2 , Yongzhi Liu 1
(1.State Key Laboratory of Frozen soil Engineering, Cold and Arid Regions Environmental and Engineering
Research Institute, Chinese Academy of Science, Lanzhou, Gnasu, China,730000;
2.Management Center of Qinghai-Tibetan Railway Geermu, Qinghai, China,861000)
Abstract : Block-stone embankment is one of techniques for protecting permafrost of
Qinghai-Xizang Railway, and has been used in about 60% of the sections overlying warm
permafrost with high ice content. In order to evaluate the cooling effectiveness of the BSE,
seven monitoring sites of the soil temperature beneath the block-stone embankment were set up
in Qinghai-Xizang Railway. According to analysis of monitoring in recent three year, it is
concluded that it is advantage to cooling roadbed for block stone embankment, but the different