Study on the shear property of nano-MgO-modified soil

To study the relationship between nano-MgO and soil shear property, the nano-MgO was evenly mixed in the soil to perform the triaxial consolidation draining shear test. Then the microscopic soil granules on the shear planes were observed through the scanning electron microscope. The soil water content was 10% and soil dry density was 1.5 g/cm3, different dosages of nano-MgO, i.e., 0, 2, 4, and 6% were put into the soil samples. The result of triaxial consolidation draining shear test showed that, under low confining pressure and more nano-MgO dosage, the stress–strain relationship of nano-MgO-modified soil turned from hardening to softening. The incorporation of nano-MgO can effectively improve the soil failure strength and cohesive force, and the increasing dosages of nano-MgO had a positive effect on soil shear strength and cohesive force, but little effect on internal friction angle. The analysis of scanning electron microscopy showed that the dosage of nano-MgO can reduce the void ratio of soil and reinforce the cementation between soil granules to change the shear property of soil.