Damage analysis of the cut-off wall in a landslide dam based on centrifuge and numerical modeling

A concrete cut-off wall has been recently used in a landslide dam as an anti-seepage measure. Due to it is under a complex loading condition, the wall may undergo inelastic straining and have a potential of cracking. Several centrifuge model tests and numerical simulation are conducted to investigate the damage behavior of the cut-off wall. The numerical method of concurrently modelling small cracks in the cut-off wall and the overall landslide dam based on the finite element method (FEM)-Peridynamics (PD) multiscale coupling method is confirmed to be effective by the centrifuge model tests. The cut-off wall buried in a landslide dam bears a bending effect under lateral loadings in the absence of overlying fill. The lower part of the wall may have a potential to form cracks induced by large bending moments. The wall is in a tension-shear failure mode with an inclined crack. A parametric study demonstrates that properties of the wall and the soil have a significant effect on the damage behavior of the wall. Also, creep deformation of the dam body does not elongate the crack significantly, but it expands the width of the crack. The crack tends to stabilize over a period of time.