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以改性处理减轻饱和黄土的液化势为目标,通过对不同配比的水泥改性黄土进行SEM细观结构测试和动三轴液化试验,研究了水泥改性黄土的液化特征,得出了不同配比水泥改性黄土的动残余应变和动孔隙水压力发展趋势,分析了水泥固化饱和黄土的物化机制,并基于试验结果,提出了水泥改性黄土的最佳配比。结果表明:水泥改性处理在黄土中形成了凝块状胶接结构,优化了土中孔隙分布,增大了土体的结构强度;水泥对土体的密实效应、掺加水泥导致的细粒增加和离子交换对黄土结构的胶结效应和黏粒增加对土中游离水的吸附作用共同提高了水泥改性黄土地基的抗液化稳定性;水泥掺量大于3%后,水泥改性黄土的动残余应变和孔隙水压力随着振次的增加均增长缓慢,且在m=5%时峰值最小,表明5%是水泥改性黄土地基抗液化处理的最佳配比。
The aim is to reduce the liquefaction potential of saturated loess by modified treatment. The microstructure of cement-modified loess with different proportions is studied by SEM microstructure test and dynamic triaxial liquefaction test. The liquefaction characteristics of cement-modified loess are studied, Based on the experimental results, the optimal proportion of cement-modified loess is proposed. The results show that the cement modification process forms a clinker-like cementing structure in the loess so as to optimize the distribution of the pores in the soil and increase the structural strength of the soil. The compact effect of the cement on the soil, the fines The effect of increasing and ion exchange on the cementation of loess structure and the adsorption of free clay on the loess soil increase the anti-liquefaction stability of cement-modified loess foundation. When the content of cement is more than 3%, the dynamic behavior of cement-modified loess The residual strain and pore water pressure increase slowly with the increase of vibration times, and the peak value is the smallest when m = 5%, which shows that 5% is the best ratio of anti-liquefaction treatment for cement-modified loess foundation.