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Yang F.-X.,Engineering Co. of Daqing Oilfield | Zhang X.-F.,Jilin University | Leng Y.-F.,Jilin University | Zhao Y.-M.,Engineering Co. of Daqing Oilfield
Yantu Lixue/Rock and Soil Mechanics | Year: 2011

Thawing settlement deformation is one of the main freezing damage for the structure in permafrost region. The actual thawing settlement is the superposition of two parts: thaw settlement and compression settlement. The volume compression coefficient is the key calculation parameter in estimating the compression deformation. Basing on the 286 thawing compression test data of undisturbed frozen soil samples, it has put forward various types of regression equations including linear equation, binomial equation and logarithmic equation and these equations represent the relationship of volume compressibility and dry density of six sorts of soil on the two different pressure sections 0-100 kPa and 0-200 kPa. These soil types are fine gravel, sand, silt, clay, peaty clay and peat. On this basis the empirical volume compression data table of the six sorts of soils is given out; meanwhile, the problems in recommended methods of specifications are pointed out.

Leng Y.-F.,Jilin University | Sun Y.-H.,Jilin University | Yang F.-X.,Engineering Ltd of Daqing Oilfield | Jiang L.,Engineering Ltd of Daqing Oilfield | Zhao Y.-M.,Engineering Ltd of Daqing Oilfield
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2011

Unfrozen water content is not only an important evaluation index of water migration in frozen soils, but also a common parameter in thermotechnical calculation. The principles of two unfrozen water measurement methods are analyzed respectively, which are temperature measurement method and calorimetric method, and some problems on principle of temperature measurement method are put forward. Unfrozen water content at any temperature can be obtained by calorimetric method, while by temperature measurement method it can only get the initial water content at its initial freezing temperature, as the curve can not reflect the unfrozen water variation with temperature. The contrast test of the two methods are carried out using six samples which contains different water content. The results show that there is a uncertainty in the result obtained by temperature measurement method. Therefore the calorimetric method is suggested to use if the test condition permitted.

Loading Engineering Co. of Daqing Oilfield collaborators
Loading Engineering Co. of Daqing Oilfield collaborators