Numerical Simulation on Gentle Dip Slope Deformation Caused by River Erosion

This study investigated the creep deformation of a gentle dip slope induced by river erosion. In the Ai Liao River (Southern Taiwan), more than 20 rainfall events have induced massive landslides in the dip slope terrain as a result of lateral erosion of the river channel. Numerical simulations revealed that when the riverbank cutting angle is less than 30 degrees, only circular slip and creep folds occur in the slope, with multiple small folds occurring from the toe to the top of riverbank (but no rapid damage occurs). When the river cutting angle is between 30 degrees and 45 degrees, drag bending folds are likely to occur on the contact surface between the surface and bottom layer, and a sliding surface appears along the contact surface. Finally, when the river cutting angle is more than 45 degrees, slope movements occur, leading to significant, rapid block damage.