Improvement for soft soil by soil-cement mixing

Soft soils are well known for their low strength and high compressibility. Usually, due to sedimentary process on different environments, both physical and engineering properties (namely void ratio, water content, grain size distribution, compressibility, permeability and strength) show a significant variation. Further, they exhibit high compressibility (including an important secondary consolidation), reduced strength, low permeability and compactness, and consequently low quality for construction. Thus, the soil-cement mixing is adopted to serves as an excellent foundations, and resist stability during construction process. It has recently been used to improve the strength and deformation characteristics of these soft clays. For the abovementioned reasons, a comprehensive laboratory testing programme was carried out in order to study the effect of inclusion of cement on physical and engineering behaviour of a soft clay. A series of tests was carried out by varying proportion of Portland cement and soft clay. In this paper, the physical characteristics, index properties, unconfined compressive strength, CBR of soil-cement treated soft clay, the field conditions, the laboratory testing results in Thailand are given and discussed.