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对不同取样方式得到的上海、江苏地区海相软黏土的原状样和重塑样进行了单向压缩和等向压缩试验,分别得到各自的压缩曲线、压缩指数C c和回弹指数Cs。通过比较原状样、重塑样的归一化压缩曲线的差异,确认了结构性对软黏土压缩特性的影响。把屈服应力后的压缩曲线外延至10 kPa时的孔隙比定义为参考孔隙比e1*0,用于简单量化土的组构。根据多次单向压缩试验结果得到的压缩指数C c,建立了原状样和重塑样的压缩指数C c与孔隙比e1 0或参考孔隙比e1*0的相关方程,并通过单向、等向压缩指数的比较,认为此方程也适用于等向压缩试验结果。根据原状、重塑样压缩指数C c与参考孔隙比e1*0具有基本相同关系的结论,对原状样的结构屈服特性进行了探讨,认为原状样在压力大于结构屈服应力后,胶结已基本破坏,原状样和重塑样压缩特性差异主要是由组构的差异引起的。该研究成果,尤其是压缩指数C c与参考孔隙比e1*0的相关方程,可为工程提供重要的参考。
Unconfined compressive and isostatic compressive tests were carried out on the original and remolded specimens of marine soft clay in Shanghai and Jiangsu regions obtained from different sampling methods. Their compression curves, compressive index C c and rebound index Cs were obtained respectively. By comparing the difference of normalized compression curves of the original sample and remodeled sample, the effect of structure on the compression properties of soft clay was confirmed. The porosity ratio at which the compression curve after yield stress is extended to 10 kPa is defined as the reference pore ratio e1 * 0, which is used to simply quantify the texture of the soil. According to the compressive index C c obtained by multiple one-way compression test results, the correlation equations between the compressive index C c of the original sample and the remolded sample and the void ratio e1 0 or the reference void ratio e1 * 0 are established and the unidirectional, Comparison of the compression index, that this equation is also applicable to the results of isotropic compression test. According to the original state, the compressive index C c of the reshaped sample has the same relationship with the reference pore ratio e1 * 0. The structural yield characteristics of the original sample are discussed. The original sample is basically destroyed after the pressure is higher than the structural yield stress The differences in compressive properties of the original and remodeled samples are mainly caused by the differences in the structure. The research results, especially the correlation equation between the compressibility index C c and the reference void ratio e1 * 0, can provide important references for engineering.