PREDICTION OF THE VERTICAL PERMEABILITY COEFFICIENT BASED ON FRACTAL THEORY FOR WOVEN SLIT-FILM GEOTEXTILES

Abstract

The coefficient of vertical permeability is a common filter design criterion for woven slit-film geotextiles. According to the pipe flow theory, a permeability coefficient model has been proposed for predicting the permeability coefficient of woven geotextiles, in which the pore characteristics were described by the Sierpiński carpet fractal theory. The verification of models is performed in 12 woven geotextiles of two types using a digital image method and a vertical water permeability test of the geotextile. The influence of the pore characteristics on the permeability coefficient is further explored using univariate and multivariate analyses. The results show that the porosity model can accurately predict the total percent pore area (POA) and the POA distribution of the woven geotextiles, and the permeability model can accurately predict the permeability coefficient of the geotextiles. The permeability coefficient of geotextiles decreases with the pore area fractal dimension and the minimum pore size under the action of a single factor. The permeability coefficient increases as the maximum pore size increases. POA and maximum pore size are the most significant independent variables affecting the permeability coefficients of geotextile under the action of multifactor.