干湿循环条件下水泥粉煤灰固化南沙淤泥土试验研究

EXPERIMENTAL STUDY OF NANSHA SILT SOIL REINFORCED WITH CEMENT AND FLY-ASH DURING WETTING-DRYING CYCLES

通过水泥和粉煤灰等固化剂对南沙淤泥进行固化处理,并在模拟滨海环境下进行干湿循环试验,通过无侧限抗压强度试验、直剪试验、扫描电镜试验,研究不同干湿循环次数和不同水泥粉煤灰掺量对其力学性能和微观结构的影响。研究结果表明：固化淤泥土的内摩擦角、黏聚力、无侧限抗压强度随干湿循环次数的增加而呈现先上升后下降的特点,随着水泥,粉煤灰掺量的增加而增加。微观试验结果表明：干湿循环影响固化淤泥土中胶凝体晶体颗粒的生成,从而影响固化土结构的致密性。

Improved by cement and fly ash and other curing agents,and wetting-drying cycling tested in simulated seawater environment,sludge of Nansha was implemented to study the impacts on the mechanical properties with times of wetting-drying cycling and volumes of cement powder fly ash through unconfined compressive strength test,direct shear test and electron microscopy scanning test. The research suggested that the internal friction angle,cohesion and unconfined compressive strength of solidified silt soil firstly increased,and then decreased with the times of wetting-drying cycles,while they increased with the increase of cement and fly ash contents. The results of microscopic experiments showed that the wetting-drying cycling could affect the formation of the crystal particles in the solidified silt soil,which influenced the compactness of solidified soil structure.