广义吸力和非饱和土的统一变形理论

Generalized Suction and Unified Deformation Theory for Unsaturated Soils

本文首先推广了吸力的概念，把一切增加颗粒间抗滑阻力的因素都称为广义吸力，在此基础上把饱和土的有效应力原理推广为广义有效应力原理。接着把饱和扰动土的孔隙状态定义为稳定状态，并提出了广义吸力的丧失将促使欠压缩土和超压缩土均向稳定状态发展的理论。然后建议了一个能同时描述湿陷和湿胀特性的本构模型，并通过模拟试样在不同的加荷方式和浸水共同作用下的表现，说明建议的理论可以描述黄土和膨胀土的基本变形特性。

in this paper, first of all, the concept of suction is generalized to include all factors which can increase the resistance against sliding between soil particles, and a principle of generalized effective stress is proposed for unsaturated soils based on this generalized suction concept. Next,assuming that the void ratio Of saturated disturbed soil sample is uniquely determined by the stress state and defined as stable void ratio, a stable state theory is formulated which POstulates that during the loss of generalized suction the void ratio tends to stable void ratio, i. e.the under-compressed soils contract but the over-compressed soils expanse. A constitutive model enable to simulatethe process of loss of generalized suction is suggested, and the behaviours of a collapsible soil and an expansive soilunder loading and/ or wetting are analyzed with this model.