关于非饱和土本构研究的几个基本规律的探讨

Discussion of fundamental principles in unsaturated soil mechanics

非饱和土是土不同状态的一种,所有的土都可能对于水处于部分饱和状态。因此,理想的土本构模型应该能够预测在所有可能的孔压和应力范围内土的性质;同时,也可以描述在该范围内任一的应力和水力路径。在过去大约20 a的时间中,非饱和土本构性质的研究经历了重大的发展,主要表现在以下几个基本理论方面:体积变化、剪切强度、屈服应力、土水滞回及水力学性质的耦合等。拟从对试验数据的预测效果、各理论间的一致性以及饱和与非饱和状态的连续性3个方面,对非饱和土本构基本理论的研究现况进行分析、归纳。

An unsaturated soil is a state of the soils.All soils can be partially saturated with water.Therefore,constitutive models for soils should ideally represent the soil behaviours over entire ranges of possible pore pressure and stress values and allow arbitrary stress and hydraulic paths within these ranges.The last two decades or so have seen significant advances in modelling behaviours of unsaturated soils.A review of constitutive models for unsaturated soils is presented.In particular,it focuses on the fundamental principles that govern the volume change,shear strength,yield stress,water retention and hydro-mechanical coupling.Alternative forms of these principles are critically examined in terms of their predictive capacities for experimental data,the consistency between these principles and the continuity between saturated and unsaturated states.