Study on Creep Characteristics and Model of Plateau Lacustrine Peat soil

The creep of plateau lacustrine sediment peat soil has seriously affected the long-term stability and safety of buildings, so it is necessary to study its creep characteristics. Consolidated creep tests were carried out on undisturbed peat soil, and the stress-strain curves with time under different loads were obtained by different loading methods. The results show that the isochronous and log-log creep curves show that peat soil has obvious nonlinear characteristics under different loads. The strain of peat soil is simplified into linear viscoelastic and nonlinear viscoplastic. Based on the linear Kelvin creep model and empirical model, a semi-empirical and semi-theoretical consolidation creep model is established to analyze the creep behavior of peat soil. The creep samples are scanned by electron microscope to analyze the mechanism of their microstructure change under the action of load, that is, the deformation of peat soil under low pressure mainly comes from the compression of organic matter and colloid and the free water discharge, and the deformation under high pressure mainly comes from the dislocation of soil particles. The above analysis can provide reference for the prevention and control of post-construction settlement.