Abstract: Lacustrine deposited soft soils are widely encountered in the Binhu New District, Hefei City. Soil improvements are required for the new engineering development. This paper presents a new soil improvement method using Ground Granulated BlastFurnace Slag (GGBS) as an additive to solidify the lacustrine deposited soft soils. Extensive laboratory tests were performed on testing the unconfined compressive strength of the soil GGGBS mixed samples with different ratios (8% GGBS & 14%BBGS) and different curing ages (3 d, 7 d and 28 d). The results indicate that, within a practical mix ratio, the addition of GGBS will increase the strength of mixed soils and the strength also increases with the sample curing age.

Key words: soft soils, unconfined compressive strength, ggbs additives, curing age