Abstract: Coastal areas are widely distributed with muddy soil which has high moisture content, high compressibility and low strength. In order to improve the early strength of the foundation, a curing agent is used to shallow the muddy soil. Through the mixing test design, it was found that fly ash and quicklime were used as the basic curing materials, and the curing agents of sodium silicate, calcium sulfate, and calcium chloride as additives could significantly improve the early strength of solidified soil. The unconfined compressive strength of the solidified soil was used as the strength index to obtain the strength response at different ages. The optimum additive ratio was obtained through comprehensive analysis. Combined with scanning electron microscopy, the reaction mechanism and microscopic morphology were analyzed. The reinforcement effect of this curing agent meets the engineering requirement.

Key words: shallow mucky soil; curing agent; early strength; lime-fly ash; scanning electron microscopy