Analysis on Rheological Properties of Peat Soil in Kunming Area

Kunming area is adjacent to Dianchi Lake. Peat soil with high water content and high compressibility is widely distributed, rheological properties is one of the most important engineering properties of peat soil. However, compared with the peat soils in the other areas, the peat soil in Kunming area has different properties. This paper studied rheological properties of peat soil in Kunming area by using the creep test of loading and unloading, on the basis of the strain-time curves, parting linear visco-elasticity, linear visco-plasticity and nonlinear visco-plasticity from the total deformation. Research shows that: ①The deformation is mostly composed of unrecoverable deformation and there is instantaneous elastic strain, instantaneous plastic strain in total strain; ②In low stress level,the soil is rendered as visco-elasticity. However, when the stress level is high, the performance of soil is visco-plasticity; ③By stress-strain curve clusters, yield stress of peat soil is approximate to 3.6 kPa in Kunming; ④Along with the time, modulus of linear visco-elasticity tended to be stable.