Analytical Analysis of Rainfall Infiltration Mechanism in Unsaturated Soils

To improve the understanding of the influence of hydraulic properties and rainfall conditions on rainfall infiltration mechanism and hence on the pore-water pressure distributions in single and two-layer unsaturated soil systems, an analytical parametric study has been carried out. Parameters considered in this study include saturated permeability (ks), desaturation coefficient (α), water storage capacity (θs-θr), and antecedent and subsequent rainfall infiltration rate (qA and qB). Moreover, the influence of soil profile heterogeneity is also investigated. The calculated results demonstrate that the infiltration process and pore-water pressure response are primarily controlled by both qα/ks and ks/α. Generally the larger the value of qα/ks , the greater the reduction of negative pore-water pressure in shallow soil layer. The larger the ratio of ks/α, the faster is the advancement of wetting front. Among the three hydraulic parameters, the effects of α and ks on pore-water pressure response are much more ...

[1]  D. Fredlund,et al.  Predicting the permeability function for unsaturated soils using the soil-water characteristic curve , 1994 .

[2]  Philip Broadbridge,et al.  Constant rate rainfall infiltration: A versatile nonlinear model, I. Analytic solution , 1988 .

[3]  J. Szecsody,et al.  SLEEVE AND CASING LYSIMETERS FOR SOIL PORE WATER SAMPLING , 1985 .

[4]  L. A. Richards.  Capillary conduction of liquids through porous mediums , 1931 .

[5]  A. Pullan.  The quasilinear approximation for unsaturated porous media flow. , 1990 .

[6]  Sai K. Vanapalli,et al.  THE MEANING AND RELEVANCE OF RESIDUAL STATE TO UNSATURATED SOILS , 1998 .

[7]  Charles Wang Wai Ng,et al.  A numerical investigation of the stability of unsaturated soil slopes subjected to transient seepage , 1998 .

[8]  Daniel Pradel,et al.  Effect of Permeability on Surficial Stability of Homogeneous Slopes , 1993 .

[9]  J. Rubin,et al.  Soil Water Relations During Rain Infiltration: I. Theory1, 2 , 1963 .

[10]  R. Herbert,et al.  The genesis of a numerical model for the study of the hydrogeology of a steep hillside in Hong Kong , 1982, Quarterly Journal of Engineering Geology.

[11]  Van Genuchten,et al.  A closed-form equation for predicting the hydraulic conductivity of unsaturated soils , 1980 .

[12]  J. Philip,et al.  Theory of Infiltration , 1969 .

[13]  Curtis L. Larson,et al.  Modeling infiltration during a steady rain , 1973 .

[14]  J. Parlange,et al.  Exact solution for nonlinear, nonhysteretic redistribution in vertical soil of finite depth , 1991 .

[15]  W. Green,et al.  Studies on Soil Phyics. , 1911, The Journal of Agricultural Science.

[16]  D. Fredlund,et al.  Soil Mechanics for Unsaturated Soils , 1993 .

[17]  J. Philip.  THE THEORY OF INFILTRATION: 1. THE INFILTRATION EQUATION AND ITS SOLUTION , 1957 .

[18]  Rajesh Srivastava,et al.  Analytical solutions for one-dimensional, transient infiltration towards the water table in homogeneous and layered soils , 1991 .

[19]  T. J. Marshall.  A RELATION BETWEEN PERMEABILITY AND SIZE DISTRIBUTION OF PORES , 1958 .

[20]  D. Hillel.  Environmental soil physics , 1998 .

[21]  Charles Wang Wai Ng,et al.  Influence of Stress State on Soil-Water Characteristics and Slope Stability , 2000 .