基于状态参数的筑坝粗粒土本构模型

Constitutive model for coarse-grained dam materials considering state parameter

粗粒土的应力应变关系与其密实度有着密切的关系。当前常用的粗粒土本构模型无法考虑密实度对其力学行为的影响,在粗粒土三轴试验基础上建议了一个基于状态参数的粗粒土双屈服面模型,推导了其应力应变表达式。该模型能够反映不同初始孔隙比条件下粗粒土的峰值强度、剪胀性、应变硬化或软化规律。通过与多组粗粒土三轴试验结果比较,验证了模型的适应性。

The stress-strain relationship of coarse-grained soils is closely related to soil density. The regular constitutive model cannot consider the effect of initial void ratio on mechanical behaviors of coarse-grained soils. In this paper, a two-yield-surface model is proposed for coarse-grained soils based on triaxial tests. The two-yield-surface model using a state parameter so that can reflect the influence of soil density on the peak stress ratio, dilatancy rule, strain hardening or softening rule in shearing of coarse-grained soils. The stress-strain expressions of this model were also deduced. Several kind of coarse-grained soils test results were used to verify the adaptability of the proposed model, results showed that the model predictions are consistent with test results.