Experimental and Numerical Evaluation of Clay Soils Stabilized with Electric Arc Furnace (EAF) Slag

In this paper, engineering characteristics and settlements of clay soils stabilized with EAF slag were evaluated by laboratory experiments and numerical analyses. The strength parameters obtained from laboratory tests constituted the input parameters of the numerical analyses that displayed the settlements of clay soil layers under shallow foundations. In the experimental part, clay soil was replaced with EAF slag at 30 and 50% ratios, and triaxial compression tests and one-dimensional consolidation tests were conducted at various initial confining stresses to obtain the strength parameters of the clay-EAF slag mixtures. The test results showed that partial replacement of EAF slag with clay soil provided significant improvements on the strength and compressibility parameters of the clay soils. In the numerical analyses, the settlements of clay layers under the shallow foundations were evaluated by replacing the mechanical properties of clay-EAF slag mixed soil instead of clay soil. The findings of the numerical analyses showed that the maximum excess pore pressure development in clay-EAF slag mixtures was 77% (70C-30EAF) and 90% (50C-50EAF) less than the clay soil, and the development area was shifted to the untreated part of the soil. The consolidation duration was two times shorter in 50C-50EAF specimens and the level of settlement decreased by 20% (70C-30EAF) and 36% (50C-50EAF) compared to the untreated soil.