应用空间滑动面原理改进了Lade-Duncan弹塑性模型的屈服准则及破坏准则，建立了基于非关联流动法则的改进Lade-Duncan弹塑性模型，模型参数可通过常规三轴试验获取。利用潍坊中南部平原地区某深基坑持力层的粉土UU三轴试验结果，验证了改进Lade-Duncan模型对粉土试样的适应性。改进模型较Lade-Duncan弹塑性模型能够更好地反映持力层粉土的（σ1-σ3）—ε1关系，以及应力路径的相关性与剪胀等特性。改进弹塑性模型可为该地区高层及超高层建筑粉土地基变形计算创造有利条件。

he theory of spatial mobilized plane was used to improve the yield criterion and failure criterion of Lade-Duncan elastoplastic model, and then the modified Lade-Duncan model was established based on the non-associated flow rule. Model parameters can be determined by the traditional triaxial test. The adaptability to the modified Lade-Duncan model for silt was verified based on the triaxial UU test results of the silt samples collected in the deep foundation pit of the south-central plain area in Weifang. The modified model can better reflect the relationship between（σ1-σ3）and ε1 of supporting layer of silt, and the relativity and shear dilatancy properties of stress paths. The modified model can provide reference for the calculation of silt foundation deformation of the high-rise buildings and ultra-tall buildings.

国家自然科学基金资助项目（No.51379118）