Abstract: To explore the hydraulic conductivity of lacustrine peaty soil in plateau areas, the permeability coefficients of 20 groups of soil samples from 6 sites were measured under one-dimensional compression conditions through oedometer tests. The effects of loading time, stress level, loss-on-ignition and residual fiber contents on the permeability coefficients are analyzed. The experimental results show that under the conditions of separately loading, permeability coefficient decreases with the elapsing time and tends to be stabilized in about ten days; under the conditions of stepwise loading, the permeability coefficient decreases nonlinearly with increasing consolidation pressure, and the curves of - resemble a reverse “S”. A permeability model for lacustrine peaty soil in plateau areas can be represented by expression e- , and the relations between the permeability index ( ) and initial void ratio can be described by 0.25 . The relationships among initial permeability coefficient and loss-on-ignition , residual fiber content and are more discrete, and there clearly exits a positive correlation among , , and the initial water content . Through scanning electron microscope, the mechanism of the peaty soil permeability is discussed from the pore characteristics of soil.

Key words: peaty soil, permeability properties, loss-on-ignition, permeability index, void ratio