Model tests on geosynthetic encased column stabilized slopes subjected to seepage

This study conducted a series of model tests on geosynthetic encased columns (GECs) stabilized slopes subjected to seepage to assess the effectiveness of GECs in enhancing slope stability. The model tests simulated a prototype slope with a height (H) of 10 m and a maximum groundwater level (h_w) of 8 m. The influence of the infill material within the GECs and the drainage condition at the tip of the GECs on the performance of the stabilized slopes was thoroughly examined. Digital image analysis techniques were employed to determine the displacement profile of the slope surface and to analyze the development of the failure surface at various groundwater levels. The phreatic surface within the slope was also carefully monitored and analyzed during the model tests. For the unreinforced slope, the test results indicated that as the groundwater level rose, the slope began to deform, and tension cracks developed at the top. A complete failure surface developed rapidly at maximum groundwater level (h_w = 80% H), leading to sudden collapse. The inclusion of GECs significantly reduced slope deformation and improved slope stability. GECs with drainage ability lowered pore water pressure, resulting in a lower phreatic surface. This performance was due to their superior mechanical and hydraulic properties.