The liquidity index is a crucial factor in geotechnical engineering
used to assess soil behavior under varying loading conditions. It
provides valuable information about a soil's deformability when
subjected to loads, which is vital for structural and foundation
design. In the domain of soil-cement, especially within the deep
mixing method (DMM), various factors influence the strength of
cement-stabilized soft soils. These factors include water
content, cement content, water-cement ratio (W/C), and soil
consistency. Notably, a lower W/C ratio tends to result in higher
unconfined compressive strength ( ). In the case of the Saga
lowland, where soft cohesive soil with high compressibility and
low strength is prevalent, the standard practice employs a W/C
ratio of 1.0 with a cement content of 110 kg/m³ for most projects.
However, this research introduces an innovative approach:
utilizing a W/C ratio of 1.5 with the same cement content of 110
kg/m³, through laboratory experiments. It investigates the effects
of Liquidity Index (IL), instead of soil sensitivity, and the water
cement ratio on the unconfined compressive strength of
specimens prepared using commercial kaolin clay powder.
These specimens are prepared with varying initial water content
( ), determined based on the liquid limit value ( ), to
achieve different soil states. As a result, there is a slight
reduction in strength, but it is more uniformly distributed. This
approach is designed to bolster support for the existing
infrastructure in the Saga lowland. The significance of this study
in the field of DMM lies in advocating for an increased W/C ratio
to ensure not only the quality of the mixture but, more
importantly, the uniformity of strength within the columns. In this
context, the optimal ratio depends on a soil candidate
consistency parameter, such as its IL.

Kaolin clay powder, Liquidity index, Water-cement ratio, Deep mixing method