Abstract: To evaluate the stability of the high embankment over marsh peat soils, this paper presents a case history of a high fill airport runway project in peaty soils. The physical and mechanical property laboratory tests and in-situ vane shear test were performed. The engineering characteristics of peaty soils of tidal marsh phase in this region were analyzed. The similarities and differences of the shear strength index correction methods of the vane shear test between China and the United States were compared and evaluated, to demonstrate the variation of the vane shear strength along the depth and the heterogeneous of the peat soil deposition, as well as to linearly regress the relationship between the vane shear strength index and the shear strength index of the soil mass. Different shear strength indexes are used to evaluate the factor of safety of the peaty soil embankments. The principle of the high fill embankment stability evaluation is proposed, which is of reference significance for the construction of similar projects in the region.

Key words: Peat Soils, Field Vane Shear Test, Shear Strength, Correction Factor, Factor of Safety, Linear Regression