Experimental study on secondary consolidation characteristics of Kunming peat soil

Abstract

A series of conventional consolidation tests and 60 d creep consolidation tests were carried out on undisturbed peat soil samples taken from Kunming for the consolidation and secondary consolidation characteristics. The variation rule and formation mechanism of secondary consolidation parameters were analyzed in detail. Test results show that the e - lgt curves of Kunming peat soil under different consolidation pressures show an inverse S-shape, the ratio of secondary consolidation deformation to total deformation is 32.8%. With the increase of consolidation pressure p, the C a value of peat soil and general soft clay first increase rapidly to the peak value and then decrease gradually. However, different from general soft clay, the peak value of C a value of peat soil is higher which appears at the consolidation pressure of 200kPa (preconsolidation pressure of 67kPa). It is believed that this is related to the high content of organic matter and the abundant micropores in the organic matter. The C a /C c value of Kunming peat soil is 0.052, which conforms to the "C a /C c compression rule". According to the soil classification standard based on the coefficient of secondary compressibility, Kunming peat soil belongs to high secondary compressibility soil.