针对高速公路软土路基的沉降预测,介绍灰色Usher模型的原理和应用。在置换法、碎石桩和塑料排水板三种不同软基处理方式下,分别应用该模型及双曲线模型、泊松曲线模型和Gompertz模型对某工程路基工后沉降进行预测。比较四种模型计算结果显示,基于实测数据的Usher模型很好地反映出沉降变化及其趋势。其精度高于其它三种预测模型,具有一定的工程应用价值。 Aiming at the settlement prediction of expressway soft soil roadbed, the principle and application of gray Usher model are introduced. This model and hyperbolic model, Poisson curve model and Gompertz model are used to predict the post-construction settlement of an engineering subgrade by using three different soft foundation treatment methods: replacement method, gravel pile and plastic drainage board. Comparing the results of four models, the Usher model based on the measured data well reflects the change of sedimentation and its trend. Its accuracy is higher than the other three prediction models, and has certain engineering application value.