Crack growth prediction in scaled down model of concrete gravity dam

Abstract

Mixed-mode crack growth in a scaled-down model of a concrete gravity dam is investigated. An initial crack is assumed under equivalent hydraulic and self-weight loadings. The two-domain boundary element method (BEM) is applied in conjunction with the theory of linear elastic fracture mechanics (LEFM). The body force is included to simulate the weight effect of the dam on crack growth. The criteria of maximum tangential stress, minimum strain energy density function, maximum tangential strain and maximum energy release rate are used to predict the mixed-mode crack path. The numerical simulations are compared with the experimental results for the scaled down 1:40 model of a concrete gravity dam. Analytical results obtained from a cohesive fracture model using a finite element code are also discussed. It is found that the four foregoing LEFM criteria perform equally well for predicting crack trajectories, load versus crack tip opening displacement (CTOD), and load versus crack tip sliding displacement (CTSD) relations. This may be due to the dominance of the Mode I effect in crack growth as the contribution of Mode II is found to be negligibly small.