This paper presents findings of the effect of calcium bentonite (Ca-bentonite) and pulp mill fly ash (PFA) on the compressibility behavior, and microstructural evolution of organic soil. A natural soil consisting of 26% organic matter was collected from the wetlands in the Wabasca region, Northern Alberta, Canada. A various mix design was prepared for the laboratory tests with the addition of 5%, 8%, 10%, 12%, 15%, and 20% Ca-bentonite with constant 30% PFA. One-dimensional consolidation tests were carried out to evaluate compressibility behavior of the stabilized organic soil. In addition, fall cone tests were conducted to evaluate change in undrained shear streth of soil after stabilization. A series of scanning electron microscope (SEM) tests with energy dispersive X-ray (EDS) and X-ray diffraction (XRD) experiments were conducted to investigate the microstructural and chemical aspects of the organic soil treated with Ca-bentonite and PFA. The results showed that a mixture of 10% Ca-bentonite with 30% PFA was the optimum dosage for improving compressibility of organic soil regardless of the curing method. Microstructural and chemical analysis revealed that the mineralogical and morphological contents of the stabilized organic soil were affected due to the pozzolanic reaction. The results showed that Ca-bentonite and PFA were able to considerably improve the strength and compressibility of the selected organic soil.

本文介绍了钙膨润土（Ca-膨润土）和纸浆厂粉煤灰（PFA）对有机土壤的可压缩性和微观结构演变的影响。从加拿大艾伯塔省北部瓦巴斯卡地区的湿地收集了由 26% 有机质组成的天然土壤。为实验室测试准备了各种混合设计，其中添加了 5%、8%、10%、12%、15% 和 20% 的钙膨润土和 30% 的 PFA。进行一维固结试验以评估稳定有机土的可压缩性。此外，还进行了落锥试验以评估稳定后土壤不排水剪切强度的变化。进行了一系列带有能量色散 X 射线 (EDS) 和 X 射线衍射 (XRD) 实验的扫描电子显微镜 (SEM) 测试，以研究用 Ca-膨润土和 PFA 处理的有机土壤的微观结构和化学方面。结果表明，无论采用何种固化方法，10%Ca-膨润土和30%PFA的混合物是提高有机土壤压缩性的最佳用量。微观结构和化学分析表明，稳定的有机土壤的矿物学和形态学含量受到火山灰反应的影响。结果表明，钙基膨润土和 PFA 能够显着提高所选有机土壤的强度和压缩性。结果表明，无论采用何种固化方法，10%Ca-膨润土和30%PFA的混合物是提高有机土壤压缩性的最佳用量。微观结构和化学分析表明，稳定的有机土壤的矿物学和形态学含量受到火山灰反应的影响。结果表明，钙基膨润土和 PFA 能够显着提高所选有机土壤的强度和压缩性。结果表明，无论采用何种固化方法，10%Ca-膨润土和30%PFA的混合物是提高有机土壤压缩性的最佳用量。微观结构和化学分析表明，稳定的有机土壤的矿物学和形态学含量受到火山灰反应的影响。结果表明，钙基膨润土和 PFA 能够显着提高所选有机土壤的强度和压缩性。