Water infiltration may induce collapse and differential settlement in compacted loess area, therefore, it is necessary to study its permeability characteristics. The permeability curves of compacted loess with three different dry density are measured by a vertical soil column with filter paper. The results show that with the decrease of matric suction, the permeability curve of compacted loess can be divided into three stages: slow increasing, quick increasing and saturated, and the smaller the dry density is, the more obvious the characteristics of the three stages would be. The variable of the dry density affects the permeability on low suction range, the larger the dry density, the smaller the permeability coefficient. The variable of the dry density doesn't affect the permeability on high suction range. In addition, it's well known that the more the pores in the soil, the larger the permeability. Therefore the pore-size distributions of the three soils are measured by mercury intrusion porosimetry tests. The results show that the amount of micro pores is the same between loess with different dry density, the corresponding permeability are the same too. The larger the dry density, the less the small pores (1.3 μm < d < 8 μm), and the smaller the corresponding permeability. Middle and large pores make little influence to the permeability due to its low content. © 2020, China Water Power Press. All right reserved.
