Study and evaluation of the effect of adding different dosages of furnace slag on the shear resistance of backfill soil (Al-Hashoum)

Abstract

The study site was chosen due to the importance of the sand dunes, also known as "hashoum," extending along the Libyan coast adjacent to the seashore. This soil is widely used in backfilling operations. This study focused on determining the extent to which the hashoum soil found in the Qasr Ahmed area of Misrata could be improved by using varying proportions of iron and steel furnace slag. The study comprised two phases. The first phase involved conducting laboratory tests to identify the properties of the backfill soil (hashoum), including soil type, specific gravity, field density, natural water content, and other characteristics. The soil was then classified Based on the liquid and plastic limits and sieve analysis according to (AASHTO M145 and M57) standards, the soil was classified as fine sandy soil (A-3) and, according to the USCS standard, as poorly graded sandy soil (SP). The second stage involved identifying the mechanical properties. A direct shear test was conducted on a range of different percentages (0%, 2%, 4%, 6%, 8%) to determine the shear strength of the crushed soil with added slag. The results showed that the cohesion coefficient between soil particles increased with increasing slag content. This is attributed to the fact that slag increases cohesion strength, as evidenced by its addition to cement