Microbially Induced Calcite Precipitation (MICP) Biostimulation Reduces the Slope Angle Degradation of CL Soil Under Loading

Abstract

Landslides are among the most detrimental geotechnical hazards in Indonesia. Conventional stabilization methods can improve slope stability but are associated with high costs and environmental impacts. Microbially Induced Calcite Precipitation (MICP) offers an environmentally friendly approach through calcite precipitation that strengthens interparticle bonding. This study investigates the effectiveness of MICP biostimulation in reducing slope angle degradation under loading in low-plasticity clay (CL) soil. Two small-scale slope models (without treatment and MICP treatment) with an initial angle of 60° were subjected to a 125 kg loading test. Slope deformation was monitored for 160 minutes, and shear strength parameters were determined through a direct shear test. The results showed that the MICP-treated slope experienced an average angle degradation of only 2.24°, which was 47.17% smaller than that of the untreated slope (4.24°). The failure mechanism shifted from sliding to vertical cracking. The direct shear test confirmed an increase in cohesion of 90.15% and an increase in the internal friction angle of 37.05%. These findings demonstrate that MICP biostimulation can reduce slope angle degradation and modify failure patterns. The study highlights the potential of MICP biostimulation as an effective and sustainable slope stabilization technology.

Keywords: MICP Biostimulation; Slope Angle; Slope Stability; Clay Low Plasticity.