关键词: 吹填粉砂土, 蠕变行为, 模型参数, 幂函数, Burgers体模型

Abstract:

The authors research the consolidation creep characteristics of dredger fill silty sand by analyzing the effect of normal stress, dry density and sample size on its creep behavior. In comparison to the Kelvin’s model, the Burgers’s model is more reasonable to interpret the creep curve of dredger fill silty sand, so the FlCD^3D method is utilized to carry out the three-dimensional numerical simulation of its consolidation creep process. The results show that dredger fill silty sand exhibits certain creep behavior and the power functions can be used to describe the stressstrain relationship and straintime relationship. For the given dry density, the larger the normal stress is, the larger the initial strain is and the longer time it takes to stabilize. When normal stress is constant, the larger the dry density is, the smaller the initial deformation is and the shorter time it needs to stabilize eventually. The instantaneous deformation and creep rate of large size sample (Ф 200.0 mm×H200.0 mm) is larger than that of standard size sample (Φ61.8 mm×H20.0 mm) and the time needed for larger size sample to stabilize is longer. In addition, the Burgers’s model proved to be superior to Kelvin’s model is feasible to simulate the consolidation creep process of dredger fill silty sand. The achievements of this research can provide helpful reference for simulations of creep test and engineering practices related to dredger fill silty sand in coastal area.

Key words: dredger fill silty sand, creep behavior, model parameters, power function, Burgers model