Permafrost

does not spread the energy in the foundation soils below the embankment. Because of that,
when the thermal insulation is used to keep the permafrost table, the ground temperature below
the embankment rises gradually, and this will lead to heat accumulation under the insulation.
For the warm permafrost region the long-term effect of the thermal insulation layer is not good.
The thermosyphon method is a active approach and can cool the soil surrounding it by
exporting inner thermal energy in cold season, but the thermosyphon does not function in warm
season and the extension of its effect which is effective radius is limited. In some cases the
thermal insulation and the thermosyphon are used as a combination to achieve better cooling
effect so as to maintain stability of the embankment, in this way their respective advantages can
be utilized in the different season and the more accumulated “cold” can be kept in the
embankment.
In the paper, according to the observation data of the climate and geological conditions at
test site of Qinghai-Tibet railway, finite element analysis of 3-D temperature field with phase
change is conducted to study the cooling effect of 4 kinds of embankment, namely, traditional
thermosyphon embankment , 3 kinds of combined thermosyphon and insulation embankment
in which the thicknesses of the insulation are 6 , 8, and 10cm, respectively, and the position of 3
kinds of insulation in embankment is 0.4m up the natural ground surface. In term of the
analyzing and comparing temperature characteristics of each embankments in future 40 years,
the cooling effect of different embankment is given and the most rational spacing between the
thermosyphons in above 4 kinds of embankment is obtained, respectively.
Key words: permafrost, insulation, thermosyphon, temperature field, embankment
Study on Frame of Permanent Maintenance Decision Support System
for Permafrost Embankments of Qinghai-Tibet Railway
Yong-ping Yang 1,2 , Qingchao Wei 2 , Luxin Zhang 2 , Shunhua Zhou 1
(1. Key Laboratory of Road and Traffic Engineering of the Ministry of Education,
Tongji University, Shanghai, 200331;
2. Civil Engineering & Architecture School, Beijing Jiaotong University, Beijing,100044)
Abstract:Formidable nature conditions and the problem of permafrost makes the maintenance
work of permafrost embankments more difficult than that of others. Based on the GIS platform,
this paper established frame architecture of permanent maintenance Decision Support System
(DSS) for permafrost embankments of Qinghai-Tibet railway, and studied the function
implementation of system integrated specific maintenance work and information technology.
Based on the different network, this paper established the topology structure used by different
employee. Meanwhile, the design of the database contents of distributed database, treatment
and integration of various data, different form of data flow were studied. Based on these studies,
this paper put forward the architecture design of the database on the basis of the system
function, and suggested the design platform of the system. Integrating the technology of MIS,
GIS and DDS, the technology routes this paper gives realizing information management on
permafrost embankments of Qinghai-Tibet railway can fulfill the safe running demands of the
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