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为研究结构性对软黏土变形特性的影响,对上海软黏土原状样和不同制样方式得到的重塑样、泥浆样和压实样开展了压缩试验和压汞试验,确认固结压力和制样方式对软黏土的孔径大小及分布具有重要影响。试验结果表明:上海软黏土原状样的孔径分布为单峰孔径分布,孔径大小主要分布在0.01~1.00?m之间;结构性对孔径分布影响较大,随着固结压力的增大,大孔隙和中孔隙逐渐向小孔隙转化,尤其是固结压力大于结构屈服应力后,这种现象更加明显;不同制样方法得到的重塑样、泥浆样和压实样,在饱和状态下的孔径分布均为单峰孔径分布,但不同制样方式得到的土样孔径分布差别较大,压实样的孔径相对较大,泥浆样的孔径分布较为集中;随着固结压力的增大,不同制样方法在相近孔隙比下的土样孔径分布差别虽然有所减小,但仍无法达到相同或接近,即固结压力无法消除制样方式对土体孔径分布的影响。用简单表示组构的参考孔隙比对不同土样的压缩曲线进行归一化整理,得到4种土样的压缩曲线可归一化为一条相关度极高的直线,说明参考孔隙比用于简单表述土体的组构是合理、有效的。
In order to study the effect of structure on the deformation characteristics of soft clay, compression tests and mercury intrusion tests were carried out on the remolded samples, mud samples and compacted samples obtained from the original soft clay samples in Shanghai and from different sample preparation methods. The consolidation pressure The sample mode has an important influence on the pore size and distribution of soft clay. The experimental results show that the pore size distribution of the original soft clay sample in Shanghai is a single peak pore size distribution, the pore size distribution is mainly distributed in the range of 0.01-1.00 μm, and the structural effect has a great influence on the pore size distribution. As the consolidation pressure increases, The pore and mesopore gradually transform into small pores, especially when the consolidation pressure is greater than the structural yield stress. This phenomenon is more obvious. The remodeled samples, mud samples and compacted samples obtained by different sample preparation methods have the same pore size However, the distributions of pore sizes were different for different sample preparation methods, and the pore sizes of compacted samples were relatively larger and the pore size distributions were more concentrated. With the increase of consolidation pressure, Although the difference of pore size distribution of sample preparation at similar void ratio can not be reduced to the same or close, the consolidation pressure can not eliminate the effect of sample preparation on soil pore size distribution. The compressive curves of different soil samples were normalized by simply expressing the reference pore ratios of the structures. The compressive curves of the four soil samples were normalized to a straight line with very high correlation, indicating that the reference porosity ratio Representation of soil structure is reasonable and effective.