This research studies the effect of the addition of polypropylene
fibers (PF) on the properties of the swelling clayey soil. The effect
of PF on the shear strength of the clayey soil has been studied
and the results show that adding PF, up to spec
ific value,
increases the shear strength. Beyond this value of addition, the
shear strength decreases. The increase in shear strength was
about (100-110) % and the optimal addition ratio was determined.
This paper aims at investigating the effect of organic matter
content on the engineering properties of the soil.
The effect of the organic matter on both the consistency limits and strength have been investigated. The results show that the organic
matter increases both the plasticity and the strength of soil.
Mathematical formula is presented in which the unconfined
compression strength of the soil is related to the organic matter
content. It was concluded that increasing the organic matter
content increases the displacement corresponding to the maximum shear stress. In addition, the effect of the organic matter has been studied and the results show that the organic matter increases the compressibility of the soil.
Stabilizing the soil with cement has been investigated as well. The
results show that adding the cement to the soil improves the
strength of the soil and decreases its swelling potential.
Depending on the organic matter content, a mathematical formula
is presented to determine the required cement ratio to treat the
soil to decrease its swelling potential.