The complex process of soil freezing which relates to moisture field, temperature and stress field usually accompanies water migration and crystallization. The mechanism of water migration in thefrozen fringe is blurr...The complex process of soil freezing which relates to moisture field, temperature and stress field usually accompanies water migration and crystallization. The mechanism of water migration in thefrozen fringe is blurry though there have rather mature theory analyzing water migration in the unfrozen zone and fully-frozen zone. It is a visualized and easy method to calculate the potential gradient of frozen fringe by frost heave amount, the duration of the steady state of frost heaving and the coefficientof permeability based on the Darcy penetration theory, not directly considering water driving force, ice segregation temperature and the thickness of frozen fringe. The method isfeasible by comparing the calculated amount of frost-heaving with the test data.展开更多
By the indoor experiment research the hydraulic parameters of the saline soil (soil-water potential and coefficient of permeability), find the some characters of the soil-water potential of saline soil: for the same s...By the indoor experiment research the hydraulic parameters of the saline soil (soil-water potential and coefficient of permeability), find the some characters of the soil-water potential of saline soil: for the same saline soil at the same dry bulk density, whenever salt solution in soil, at the same liquor content the absolute value of the soil-water potential is alwaysbigger than the saltless soil. And at the same liquor content the absolute value of the soil-water potential increases with increasing the concentration of the salt liquor. And at the same concentration of the salt liquorand at the same liquor content, the absolute value of the soil-water potential of sulphatesalt liquor soil is bigger than chloride salt liquor soil. Moreover, the absolute value of the soil-water potential of calcium chlorideliquor is bigger than sodium chlorideliquor. The disciplinarian of the coefficient of permeabilityto the saline soil is that whenever saline soil the coefficient of permeabilitydecreases with increasing the salt content and the fine soil changemore obviouslythan coarse-grained soiland the sulphatesalt soil change more obviouslythan sodium chloridesalt soil.展开更多
The effective and assured measures in criteria of formulation, procedures, techniques and methods for geological prospecting of Qinghai-Xizang Railway have been made. The permafrost engineering geological investigatio...The effective and assured measures in criteria of formulation, procedures, techniques and methods for geological prospecting of Qinghai-Xizang Railway have been made. The permafrost engineering geological investigation indicate the talik and those sections with annual average ground temperature higher than 1 ℃ takes up 68.8% of total amount; the high ice content permafrost also account for 50% of real permafrost section. The distribution of permafrost characteristics is obviously influenced by altitude and latitude. The prospecting also shows the distribution of permafrost characteristics is rather complicated. Based on two predications of air temperature-rising tendency, by calculating climate model of permafrost thermal status, and comparing and analyzing geological distribution of Qinghai-Xizang Railway, the tendency of permafrost recession range has been predicated.展开更多
文摘The complex process of soil freezing which relates to moisture field, temperature and stress field usually accompanies water migration and crystallization. The mechanism of water migration in thefrozen fringe is blurry though there have rather mature theory analyzing water migration in the unfrozen zone and fully-frozen zone. It is a visualized and easy method to calculate the potential gradient of frozen fringe by frost heave amount, the duration of the steady state of frost heaving and the coefficientof permeability based on the Darcy penetration theory, not directly considering water driving force, ice segregation temperature and the thickness of frozen fringe. The method isfeasible by comparing the calculated amount of frost-heaving with the test data.
文摘By the indoor experiment research the hydraulic parameters of the saline soil (soil-water potential and coefficient of permeability), find the some characters of the soil-water potential of saline soil: for the same saline soil at the same dry bulk density, whenever salt solution in soil, at the same liquor content the absolute value of the soil-water potential is alwaysbigger than the saltless soil. And at the same liquor content the absolute value of the soil-water potential increases with increasing the concentration of the salt liquor. And at the same concentration of the salt liquorand at the same liquor content, the absolute value of the soil-water potential of sulphatesalt liquor soil is bigger than chloride salt liquor soil. Moreover, the absolute value of the soil-water potential of calcium chlorideliquor is bigger than sodium chlorideliquor. The disciplinarian of the coefficient of permeabilityto the saline soil is that whenever saline soil the coefficient of permeabilitydecreases with increasing the salt content and the fine soil changemore obviouslythan coarse-grained soiland the sulphatesalt soil change more obviouslythan sodium chloridesalt soil.
文摘The effective and assured measures in criteria of formulation, procedures, techniques and methods for geological prospecting of Qinghai-Xizang Railway have been made. The permafrost engineering geological investigation indicate the talik and those sections with annual average ground temperature higher than 1 ℃ takes up 68.8% of total amount; the high ice content permafrost also account for 50% of real permafrost section. The distribution of permafrost characteristics is obviously influenced by altitude and latitude. The prospecting also shows the distribution of permafrost characteristics is rather complicated. Based on two predications of air temperature-rising tendency, by calculating climate model of permafrost thermal status, and comparing and analyzing geological distribution of Qinghai-Xizang Railway, the tendency of permafrost recession range has been predicated.
