Speakers
Description
Unsaturated soils typically rely on soil water characteristic curves for characterization, but the experimental determination of these curves is time-consuming and expensive. Microbial-induced calcite precipitation, an environmentally friendly soil improvement method, is gaining traction. This study explores the effects of bio-cementation and compaction on the soil water characteristics of lateritic soil treated with Bacillus megaterium suspension densities. Additionally, it aims to predict soil water retention curves using Brooks-Corey (BC), van Genuchten (VG), and Fredlund-Xing (FX) models. Results show that during WAS compaction, the VG fitting parameter 'm' decreases to 0.18 at 6.0 × 108 suspension densities, differing from other methods. A similar trend is observed for the van Genuchten curve-fitting parameter 'n.' The VG parameter 'α' peaks at 0.213 during WAS compaction, contrasting with other methods. Generally, BC air-entry suction value (ψa) increases with higher B. megaterium suspension densities. The FX parameter 'a' peaks within the range of 1.5 × 108 - 6.0 × 108 suspension densities; and thereafter varied marginally up to 24 × 108 bacteria suspension density. FX parameter 'b' initially decreases and then increases with bacterial suspension densities, except for slight deviations. In summary, BC, VG, and FX models predict volumetric water content effectively, but VG may overestimate at lower suction pressures, while BC consistently under predicts at higher suction across all compaction schemes.