Quantitative assessment on the variation of compressibility of Wenzhou marine clay during destructuration

Abstract

A series of oedometer test were performed on both undisturbed and remolded specimens of Wenzhou marine clay to quantitatively investigate the degradation of soil structure during compression. The laboratory tests show that the swell index of both natural and remolded Wenzhou marine clay increase with the increase in consolidation stress. Hence, the normalizing parameter ‘swell sensitivity’, termed as the ratio of the remolded to the natural swelling index, can only be regarded as a qualitative parameter. On the other hand, the normalized stress sensitivity has a good parabolic relationship with the consolidation stress during destructuration. This result indicates that the stress sensitivity can be used as a quantitative interpretation of the degradation of soil structure for natural Wenzhou marine clay. Comparison between stress sensitivity and additional void ratio during destructuration shows that the variation of soil structure during destructuration represented by stress sensitivity and additional void ratio are essentially the same. In addition, the parameter used in formulating the variation of stress sensitivity with the stress level is correlated with natural void ratio and void ratio at liquid limit.