GEP prediction of the cracking zones in earthfill dams

One of the important factors which control the possible cracking zone in earth dams is the geometry of valley cross section. This research uses genetic express programming (GEP) for finding the best equations for the relationship between the width and depth of possible cracking zone and geometric parameters of valley cross section, such as the invert width, dam height, and the height and width of the bench and bank slopes. The GEP method can produce precise equations without asking for the assumption of the form of the equation. Four output variables of GEP are the depth and width of tension stress zone, D 0 and W 0 , respectively, and the depth and width of tension strain zone, ∆ and C , respectively. The necessary data are produced by simulating different conditions. The correlation coefficient ( R 2 ) of extracted equations by GEP is 0.95, 0.9033, 0.9262, and 0.9212 for D 0 , W 0 , Δ , and C , respectively. This shows the excellent capability of the GEP method. Also, according to the sensitivity and parametric analyses, the slopes of valley cross section, θ and β , are the most effective parameters on cracking of the dam.