Permafrost

⎛
⎜ 1 ⎛ ⎞
⎜
ε
σ = Eε
exp − ⎟
⎜ n ⎜ ⎟
⎝ ⎝ ε f ⎠
Based on this constitutive model, stress-strain curves of the frozen sand soil with different
volumetric percentage of ice at different temperatures are calculates. The results look highly
consistent with the experimental data, which indicates that this model can well describe the
mechanical characters of frozen soil.
the experimental data the calculated data
Fig.1 Compared curve of stress-strain of frozen
sand soil under different temperature ( κ i =0.05)
Key words: frozen soil, constitutive model, frozen fringe, moisture migration, damage
Mixed Environment Developing Research on the Distributed
Qinghai-Tibet Railroad GIS
Jianwen GUO, Min FENG, Qingsheng SHANG, Yingchun GE
( Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy
of Sciences, Lanzhou 730000, China )
Abstract: A distributed GIS system, which is the base of the Qinghai-Tibet railroad model
platform (named ‘Digital Roadbed’), has been built presently by developing with
IDL(Interactive Data Language), C# and SDE(Spatial Data Engine) environment. This
application system is used to support the construction and research activities of Qinghai-Tibet
railroad which is the highest plateau railroad in the world.
A number of approaches can be adopted to implement distributed GIS applications. But it’s
difficult to strike a proper balance between the performance, developing difficulty and
developing cost due to the special requirements of the Qinghai-Tibet Railroad GIS application
on the spatial data manipulation, security, and so on.
IDL is a kind of new type object-oriented interactive data manipulating language base on
matrix, and it has powerful matrix-based computing abilities and is with a big function library.
n
⎞
⎟
⎟
⎠
Fig.2 Curve of stress-strain under different
temperature
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