Abstract

The curing stress can significantly improve the engineering properties of cement-treated dredged soil (CDS). Based on the large-scale consolidation tests, this study investigated the settlement pattern of CDS under the curing stress of 0–100 kPa, and the pressure dissipation and chemical properties of pore water were also explored. The results showed that the application of curing stress greatly accelerated the settlement of CDS and significantly reduced its void ratio, however, the consolidation efficiency gradually weakened with the increase of cement content. With the curing stress increasing, the completion time of primary settlement of CDS was prolonged, and the pH and EC values of the pore water both gradually increased. The void-ratio reduction of CDS during stress curing arises from the combined effect of mechanical compression and chemical filling, and the two effects have different contributions to the reduction of void ratio at different consolidation stages. Moreover, the effects of curing stress on the microstructure of CDS were also investigated by the scanning electron microscopy (SEM) and mercury intrusion porosimeter (MIP) tests. The results show that with the curing stress applied, the volume of large pore in CDS significantly decreased and the structure became denser.

摘要

养护应力可显着改善水泥处理疏浚土（CDS）的工程性能。本研究在大规模固结试验的基础上，研究了0~100 kPa养护应力下CDS的沉降规律，并探讨了孔隙水的压力耗散和化学性质。结果表明，养护应力的施加大大加速了CDS的沉降，显着降低了其空隙率，但随着水泥掺量的增加，固结效率逐渐减弱。随着养护应力的增大，CDS初次沉降的完成时间延长，孔隙水的pH值和EC值均逐渐升高。应力固化过程中CDS孔隙率的降低源于机械压缩和化学填充的共同作用，两种效应对不同固结阶段孔隙率的降低有不同的贡献。此外，还通过扫描电子显微镜（SEM）和压汞仪（MIP）测试研究了固化应力对CDS微观结构的影响。结果表明，随着固化应力的施加，CDS中大孔的体积显着减小，结构变得更加致密。还通过扫描电子显微镜 (SEM) 和压汞仪 (MIP) 测试研究了固化应力对 CDS 微观结构的影响。结果表明，随着固化应力的施加，CDS中大孔的体积显着减小，结构变得更加致密。还通过扫描电子显微镜 (SEM) 和压汞仪 (MIP) 测试研究了固化应力对 CDS 微观结构的影响。结果表明，随着固化应力的施加，CDS中大孔的体积显着减小，结构变得更加致密。