In this research, the subsoil characteristics and
geotechnical issues have been evaluated for ground
improvement, land development and design facilitation of
Matarbari Ultra Super Critical Coal-Fired Power
Project, Bangladesh. The subsoil conditions and
geotechnical issues are addressed by determining the
geotechnical parameters of soil. The soil characteristics
are obtained from soil investigation and executed under
land development for the procurement of power plant
facilities. The American Society for Testing and Materials
(ASTM International) standard is used to estimate all the
soil parameters in field and laboratory tests. The
measured soil properties establish the area consists
mainly of two types of soils, i.e., Cohesive Clayey and
non-cohesive Sandy soils. The cohesive soils are mostly
composed of gray to dark gray CLAY, CLAY with Sand,
SILT with Sand, and Sandy CLAY with fine to mediumgrained Sand. The upper cohesive soil layer (Ac-1) is very
soft to soft, normal to slightly consolidated with low
undrained cohesion. This layer is expected to have a high
potential for differential settlement because of the
proposed design load. The lower cohesive soils (Ac-2 and
Ac-3) are firm to very stiff and moderately over
consolidated. These soils have moderate to high shear
strengths with low compressibility relating to the
expected range of the design loads. The non-cohesive
Sandy soils consist of dark gray to gray SAND, SAND
with Silt, Silty SAND, and Clayey SAND. The Sandy soils
are poorly graded and loose to very loose at the upper
part (As-1) and medium dense to dense in lower parts
(As-2 & As-3) that expect less immediate settlement when
a load placed on that. Geotechnical site conditions are
challenging and deplorable. The soft soil layer Ac-1 (with
As-1) complicates the design, especially in terms of
foundation soil instability and settlement for certain
structure types. Ground improvement techniques such as
prefabricated vertical drain (PVD) and deep mixing
method (DMM) can be applied to mitigate these
challenges and for the improvement of the soft ground of
the project area.
Keywords : Soft Soils, Soil Properties, SPT, CPT, Shear Strength, Consolidation, Settlement, Ground Improvement.