Soft soils often cause difficulties in construction operations with their low
strength, low strength, and high compressibility. However, the engineering
properties of these soils can be enhanced by soil stabilization. This research is
carried out to study the effects of using hydrated lime and Portland cement for
stabilization of soft clay soil collected from the cleaning of Mowais canal bed in
Zagazig, Egypt. Two types of experimental testing are performed on the natural and
stabilized soils. Unconfined compression strength tests are conducted on treated
and untreated soft clay samples. In addition, model footing tests are also conducted
on the untreated and treated soft soils.
Unconfined compression test results showed that mixing hydrated lime
and Portland cement with soft clay soils are effective in increasing the treated soft
soil strength and reducing its compressibility. Soils treated with high dosage of
cement (from 7% to 10%) showed lower effectiveness of lime. However, for low
dosage cement (4%), the lime effectiveness is significant. Curing time has a
noticeable impact on the strength of the cement-treated samples and cement-lime
mixture treated samples. Model tank tests are performed to study the effect of
treated soft clay with 4% cement + 4% lime on the settlement of (10*10 cm) square
model footing. Results showed that the measured settlements in treated soils are
remarkably lower than the untreated ones especially when increasing the depth and
extension of treated zone under footing.