化学改性联合真空预压法加固吹填土试验分析

通过开展室内真空预压模型试验和微观测试，针对黏粒含量较高的吹填土，探讨分析了化学改性联合真空预压法的加固效果及其机制。结果显示：经过化学改性后，吹填土的液限及塑性指数显著降低，渗透系数明显增大；此外，微观测试结果显示，经过化学改性后，改性外掺剂与吹填土颗粒间发生复杂的化学反应，吹填土颗粒表面附着大量的难溶物，使其表现为典型的团粒结构，孔隙直径明显增大，土体的渗透性显著提高；与常规真空预压法相比，化学改性联合真空预压法处理吹填土的加固效果得到大幅度的提升，其中排水量最大提升幅度达17.6%，表层沉降量明显增大，加固后土体十字板剪切强度最大提高69.0%。该研究为改进真空预压法的技术发展提供了理论依据。

Experimental analysis of chemical modification combined with vacuum preloading method for reinforcing dredger fill

Aiming at the dredger fill with high clay content, a series of vacuum preloading model tests and microscopic tests were carried out in this study, to discuss the reinforcement effect and mechanism of the chemical modification combined with vacuum preloading method. The results show that the liquid limit and plasticity index of the dredger fill were both reduced notably, while the coefficient of permeability of the dredger fill was significantly increased; in addition, the microscopic tests results show that a series of complex chemical reactions happened between modified admixture and soil particles due to chemical modification, and it can be observed that a large amount of insoluble substance was attached to the surface of the dredger fill particles due to the chemical modification, which contributed to a typical aggregate structure and increasing the pore diameter, and leading to a significant improvement in the permeability of the dredger fill. Compared with traditional vacuum preloading method, the chemical modification combined with vacuum preloading method has greatly improved the reinforcement effect of the dredger fill. The maximum increases in vacuum preloading drainage and vane shear strength of the dredger fill reinforced were 17.6% and 69.0%, and the surface settlement increased significantly. This research provides a theoretical basis for improving the technical development of vacuum preloading method.