Abstract: Permeability affects the engineering geological characteristics and mechanical behavior of the soil. The permeability coefficient comprehensively reflects the difficulty of water flowing in the pores of the soil. It is not only a quantitative indicator representing the permeability of the soil, but also a necessary for the calculation of the infiltration. A basic parameter, it is quite difficult to theoretically estimate the permeability coefficient. Granite weathered soil is the rock debris that has been weathered and denuded in the original rock. It is classified into special soil according to the cause and is often used as the building bearing layer and roadbed filler. This paper studies the permeability of granite weathered soil in Rongxian County. The original soil sample and the compacted remolded soil sample were subjected to the permeability test and the mercury intrusion test. The permeability of the granite weathered soil in Rongxian County was studied, and the existing infiltration model was linked with the macroscopic parameters. The microscopic model and the mercury intrusion test were carried out. The data were combined to compare the applicability and reliability of infiltration models for Rongxian granite weathered soil, and an improved permeability coefficient estimation model was proposed.

Key words: Weathered Granitic Soils, Permeability Tests, Coefficient of Permeability, Mercury Pressure Tests