Abstract:To investigate the effect of structure on the compressibility of peaty soil in Kunming, Yunnan, a series of one-dimensional compression tests were carried out for disturbed and undisturbed soil samples with depth from 16.5 to 17.0 m. The test results show that by drawing method, the pre-consolidation pressure is 91~105 kPa, and the over consolidation ratio is 0.71~0.82, which illuminates that the soil is in the under consolidated state. The consolidation yield stress of disturbed soil samples is only 60~72 kPa, which shows that the peaty soil has strong structure. Due to the influence of soil structure, the compression index of undisturbed soil samples is less than that of disturbed ones when the consolidation pressure is small. With the increasing of consolidation pressure, the structure of undisturbed soil samples is destroyed, and the compression index is gradually increased and exceeds that of disturbed soil samples. With the increasing of load, the compression amount increases sharply, and the consolidation coefficients of both undisturbed and disturbed soil samples show decreasing trend. The secondary consolidation coefficient is 0.071~0.101, and the secondary compression coefficient is 2.00%~2.85%, which can be classified as a soil with high or very high secondary compressibility.