基于相变状态的非饱和砂土边界面本构模型  

The bounding-surface constitutive model for unsaturated sands based on the phase transformation state

作　　者：张卫华[1,2] 赵成刚[2] 傅方[2] 

机构地区：[1]北京城市学院城建学部,北京100044 [2]北京交通大学土木建筑工程学院,北京100086

出　　处：《应用力学学报》2015年第5期724-730,891,共7页Chinese Journal of Applied Mechanics

摘　　要：低围压下,由于吸力的存在,非饱和砂土相对于饱和砂土在剪切过程中会发生更大的体积变化,即剪胀,在整个应力应变行为中出现明显的剪胀和峰值特征点。基于此,本文基于相变状态定义状态参量β,考虑水力-力学性质耦合,引入模型参数,分别在一般应力空间和三轴应力空间建立非饱和砂土的边界面本构模型。结果表明:在给定围压下,剪胀随着吸力的增加而增加,并伴随着体积增大,剪切强度提高。It shows more suction-induced volume change-dilatancy during shearing for unsaturated sands under lower confining pressure compared with the saturated sands, and there exists distinct characteristic points for dilatancy and peak value. In this paper, based on the phase transformation state, state parameter β is defined and model arguments are introduced involving the hydraulic-mechanic coupling, bounding-surface constitutive models are established respectively in triaxial and general stress spaces. Finally, based on the provided models, the predictions realistically reflect the strain hardening and softening characteristics for unsaturated sands.

关 键 词：相变状态 非饱和砂土 状态参量 剪胀 边界面 本构模型 

分 类 号：TU443[建筑科学—岩土工程]