Unsaturated Frozen Soil Permeability Coefficient Test and Analysis Under the Condition of Variable Porosity

Abstract

Frozen soil permeability is one of the key issues in the process of frozen soil water properties research due to special hydrological phenomenon caused by the change of frozen soil water properties． In order to study the effect of ice content and dry density on non － closed porosity and permeability of unsaturated frozen soils， choose ice content ( 2% ，4% ，6% ，8% ，10% ，12% ，14% ，16% ，18% ，20% ) and dry sample density ( 1． 4 × 103 kg /m3 ，1． 5 × 103 kg /m3 and 1． 6 × 103 kg /m3 ) as a single variable factor to measure frozen soil permeability coefficient． The water level test method was used to determine the permeability coefficient of frozen soil，and the experimental study on the permeability coefficient of unsaturated frozen soil was carried out． The results show that the permeability coefficient and the unclosed porosity of the unsaturated frozen soil are smaller with the increase of the ice content and dry sample density，and the range is 0． 19 － 0． 714 and 8． 55 － 19． 18 m / d． When the ice content is 20% and the dry density of the sample is 1． 6 × 103 kg /m3 ，the minimum unsaturated permafrost permeability coefficient is 8． 55 m / d and the minimum unclosed porosity is 0． 19．

Keywords

• ice content; unclosed porosity; unsaturated frozen soil; Harbin