Abstract:
The larger area of the world is covered with soft clay; the soil type known for its high susceptibility
to a shear failure, unexpected differential settlement, and experiencing low bearing capacity which
makes it be categorized as unsuitable soil for variety of engineering use. Yet, it remained
cumbersome to suitably use soft clay soil because of its high vulnerability to the subsequent
foundation failures; which is a headache to construction stakeholders especially in the
contemporary engineering world. Similarly, majority of Jimma town’s land cover is predominantly
known for its deposit of soft clay soil which is conventionally excavated up to a certain depth and
discarded ahead of actual commencement of construction projects due to its stability concern. The
usage of soft clay soil as foundation of different engineering structures is excavated unless its
intrinsic properties are enhanced through application of appropriate improvement mechanisms
among which the cement stabilization approach is one. Hence, the study aimed at studying
deformation analysis of cement modified soft clay by using finite element method. The soil samples
were collected from three different pits located in Jimma town and laboratory tests were conducted
to determine index properties, unconfined compressive strength, one-dimensional consolidation
characteristics and shear strength parameters of the soil samples. To improve these engineering
properties of the clay soil a varying percentage of cement in the mix by 9 %, 12 %, and 15 % were
applied. Besides, the deformation analysis of the soil was assessed by using Plaxis 2D software
which operates with the principle of Finite Element Method. Therefore from finite element analysis
the vertical displacement encountered in untreated soft clay was 124 mm and the displacement of
15% of cement treated of soil is 26.77 mm. It is observed that the displacement is improved when
soft clay soil is modified with 15% of cement. There was a high difference in the magnitude of
untreated and treated soft soils this is a result of soil cement reaction and effect of curing period
of the specimen.
