水泥改性黄土的抗液化特性与机制

发布时间：2018-06-06 17:37

本文选题：水泥改性 + 饱和黄土　；参考：《岩土工程学报》2016年11期

【摘要】：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。
[Abstract]:In order to reduce the liquefaction potential of saturated loess, the liquefaction characteristics of cement modified loess were studied by means of SEM meso structure test and dynamic triaxial liquefaction test. The development trend of dynamic residual strain and dynamic pore water pressure of cement-modified loess with different ratios are obtained. The physicochemical mechanism of cement-cured saturated loess is analyzed. Based on the experimental results, the optimum proportion of cement-modified loess is proposed. The results show that the cement modified treatment forms the agglomerate structure in loess, optimizes the pore distribution in the soil, increases the structural strength of the soil, and the compaction effect of cement on the soil. The cementation effect of fine particles and ion exchange on loess structure caused by cement and the adsorption of free water by clay increase improve the liquefaction stability of cement modified loess foundation, and the cement content is more than 3%, and the cement content is more than 3%. The dynamic residual strain and pore water pressure of cement-modified loess increase slowly with the increase of vibration frequency, and the peak value is the smallest at m = 5, which indicates that 5% is the best ratio for anti-liquefaction treatment of cement-modified loess foundation.
【作者单位】：中国地震局(甘肃省)黄土地震工程重点实验室;兰州大学土木工程与力学学院;中国地震局兰州地震研究所;
【基金】：地震科技星火计划项目(XH16038Y) 国家自然科学基金项目(51408567,51478444,41472297)
【分类号】：TU444

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