eng Science and Education Publishing American Journal of Civil Engineering and Architecture 2328-3998 2024-03-12 12 2 24 29 10.12691/ajcea-12-2-1 AJCEA20241221 article Donzala D. Some donzdavids@gmail.com 1 2 Ohindemi G. Yameogo 3 Magai N. Thon 4 Department of Civil Engineering and Architectural Design, Saga University, Saga, Japan Faculty of Exact and Applied Sciences (UFR-SEA), University Joseph Ki-Zerbo, Ouagadougou, Burkina Faso Department of Civil Engineering, Yokohama National University, Yokohama, Japan 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 soil candidate consistency parameters, cement content, water-cement ratio (W/C), mixing time, and curing time. Notably, a lower W/C ratio resulted in a higher unconfined compressive strength (qu). However, in the context of improving soft and cohesive soils through DMM, a W/C ratio of 1.0 has conventionally been recommended due to its favorable resistance. In the case of the Saga lowland, where a soft cohesive soil with high compressibility and low strength is prevalent, the standard practice employs a W/C ratio of 1.0 with a selective amount of cement for different layers, in most projects. This research introduces an innovative approach: utilizing a higher W/C ratio of 1.5 with a cement content of 110 kg/m³, to fulfill the standard strength requirement and above all, to have a well-distributed strength inside the material. This could prevent the lateral displacement of the soil-cement columns. Through laboratory experiments, this paper investigates the effects of increasing W/C on the strength distribution. As result, the comparison between the needle penetration strength (qunp) /C= 1 and 1.5 showed that the latter represents a slight reduction in strength, but it is more uniformly distributed. This approach is designed to a 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 also, more importantly, the uniformity of strength within the soil-cement columns. https://pubs.sciepub.com/ajcea/12/2/1/ajcea-12-2-1.pdf water-cement ratio strength distribution soil-cement material needle penetration index