Strength homogenization and slope stability analysis of expansive soils with native cracks

Native crack is the key factor affecting the stability of expansive soil slope and pose a potential threat to the safety of major projects. The research is based on an expansive soil slope in the Nanyang section of the South-to-North Water Diversion Project. The strength parameter expectations of multi-sized crack units, which are randomly distributed and homogenized, are determined. In light of the progressive slope failure process in the slope failure zone, an enhanced local dynamic strength reduction method is proposed for stability analysis. A comparative analysis was conducted to ascertain the stability of expansive soil slopes with and without native cracks. The findings revealed that the expansion of the plastic zone in slopes with native cracks is more pronounced than in those without cracks. The plastic zone undergoes significant development along the distribution area of native cracks, and native cracks themselves have been shown to significantly weaken slope stability, reducing the slope safety factor by 37.8\%. Native cracks located in close proximity to the potential sliding surface, particularly at the foot and top of the slope, have been observed to induce substantial concentrated displacement and shear strain increments within the slope adjacent to these cracks.