饱和砂土相变状态边界面本构模型

Bounding-surface constitutive model for saturated sands based on phase transformation state

为了很好地描述砂土的应力应变特征,通常利用以临界状态孔隙比为基础的状态参数建立弹塑性本构关系,但是对于密砂排水试验,临界状态参数很难测到。相变状态作为一特征状态,相关参数较容易测得。基于相变状态定义状态参量,并考虑应力诱发的各向异性,建立饱和砂土的边界面本构模型。最后,利用提出的模型参数得到的模拟结果与试验结果相吻合,较好地反映了密砂的应变强化和软化力学特征。

To well describe the stress-stain behaviour of sands, generally, a state parameter based on the critical state void is used to establish the elastoplastic constitutive relations. However, it is difficult to obtain the critical state parameter in the triaxial drained tests for dense sands. For the phase transformation state, being a characteristic state, its related parameters are easy to be measured. Based on the phase transformation state and considering the stress-induced anisotropy, the state parameter is defined, and a bounding-surface constitutive model for saturated sands is established. Finally, utilizing the provided model parameters, the simulated results fit well with the test ones and realistically reflect the strain hardening and soitening characteristics for dense sands.