Physical and Computational Modelling of Geosynthetic-Reinforced Model Slopes in Shaking Table Tests

Abstract

The effectiveness of tensile reinforcement in controlling the deformations of soil slopes under sinusoidal base shaking conditions is studied through model tests carried out on shaking table and the results are analyzed using computational modelling based on Newmark's rigid block analysis. The acceleration and frequency of shaking are varied in different model tests, simulating low and high frequency seismic events of different accelerations. To control the acceleration amplifications and displacements, slope models were reinforced using geogrids placed at different heights of the model. While unreinforced slopes showed higher seismic response at low-frequency high-acceleration motions, exhibiting a sudden flow slide type of failure, reinforced slopes showed very less deformations and stayed stable during all events. Slope deformations were computed using Newmark's rigid block analysis, considering the peak and residual yield accelerations of the model slopes. The deformations computed using modified Newmark's analysis are in good agreement with the measured deformations for unreinforced cases at all frequencies and for reinforced cases at lower frequencies. The analytical models overpredicted the seismic deformations of reinforced slopes at higher frequencies due to the possible alterations to interface shear mechanisms, leading to a significant difference in actual and computed yield accelerations.