Effect of the chemical compounds of soil on the stability of excavation wall: A case study

Chemical compounds of soils can remarkably affect the stability of the excavation wall. This is highlighted in soils with fine grain materials. Inter-particle chemical cementation (IPCC) increases soil cohesion and, in turn, provides more stable excavations. This study evaluates the effect of soil chemical compounds on the stability of an excavation excavated in the west of Iran, Kermanshah city. It adopted the 2D finite element method (2DFEM) to evaluate the physical stability of the excavation. In the excavation examined here, the maximum depth that could be excavated with no need for support was 36m. In contrast, according to simulation results, the maximum possible depth for an excavation with soil cohesion of 6kPa and friction angle of 33 degrees, derived from direct shear test, is 6m. As per the results of this investigation, iron oxide, aluminum oxide, and silicon oxide increase the soil's cohesion containing the clay mineral montmorillonite by 10 folds and increase its shear strength by 127%.