Electronic Journal of Geotechnical Engineering   2015 年 20 卷 22 期

2015

This paper proposes solidification schemes for soft clay with different initial conditions of water content and organic matter content. Response surface methodology (RSM) based on central composite rotatable design (CCRD) was employed for experimental arrangement of a two-stage solidification research. Cement was the main solidifying agent and gypsum, lime and sodium carbonate were additives. At the first stage, for the initial water content as 45%, humic acid content as 6%, and cement content as 15%, the three admixtures were selected as the three independent variables while response values were the corresponding 90-day unconfined compressive strength values. Optimization indicated that the optimal ratios for gypsum, lime and sodium carbonate were 5.03: 5.08: 0.83. The composite material with this ratio was named as CX-13. At the second stage, organic matter content, initial water content, cement mixing ratio, and CX-13 mixing ratio were selected as the independent variables while response values were the corresponding 7-day unconfined compressive strength values. A quantitative model of 7-day strength considering all the four independent variables was constructed. Subsequently, an optimization analysis was performed for the case of soil with organic matter content of 13% and initial water content of 45%. For this case, incorporation of CX-13 was seen to promote strength development once the mixing ratios of cement and CX-13 meet the requirement.