Seepage analysis using random fields through earth dams and finite element method

Abstract

This paper presents the seepage analysis through three popular types of earth-fill dams (homogeneous, central-core and inclined core), whose hydraulic conductivities are considered as spatially random.  This study focuses on evaluating two important parameters of seepage which are the flow rate and gradient. More specifically, the governing equation of seepage through earth-fill dams is solved using finite element analysis within a popular software, i.e. SEEP/W. The hydraulic conductivies are randomly generated based on the relevant probability density function with its mean and coefficient of variation. The generation of the random numbers is coded using C# and integrated into SEEP/W. Next, the Monte Carlo simulations are applied, including statistical techniques for assessing the results. These outcomes then are compared with ones resulted from the determisnistic calculations. Hence, within all three types of dams, there is a probability of 100 % in which the flow rates calculated from the random method are greater than ones from the deterministic method. As a meanwhile, there is a probability of about 50 % in which the gradients calculated from the random method are greater than ones from the deterministic method. The frequency distributions of the flow rates fit well the normal distributions meanwhile the ones of the gradients show a right-skewed trend.