考虑参数简化的修正邓肯-张模型

邓肯-张非线性弹性模型被广泛应用于计算围堰修筑、土石坝等水利工程中粗粒土的应力-应变关系。然而,邓肯-张模型参数相对较多、计算结果往往不能充分体现土的剪胀特性。为解决上述缺陷,本文以邓肯-张模型为基础,提出了参数形式更为简化的应力-应变表达式,并基于沈珠江模型采用二次抛物线形式对应变进行描述,同时对该模型参数形式进行了改进,建立了反映土体体应变-轴向应变关系的体积比表达式。最后通过采用粗粒土和粘性土的试验结果对改进模型进行验证。结果表明：理论计算结果与试验结果吻合较好,改进的模型能够更好的反映土的体应变特征和应力-应变关系,为实际工程中土体的应力-应变关系计算提供了参考。

Modified Duncan-Chang Model Considering Simplification of Parameters

The Duncan-Chang nonlinear elastic model is widely used to calculate the stress-strain relationship of coarse-grained soils in water conservancy projects such as cofferdam construction and earth-rock dams. However, the Duncan-Chang model has relatively many parameters, and the calculation results often cannot fully reflect the dilatancy characteristics of the soil. In order to solve the above shortcomings, based on the Duncan-Chang model, this paper proposes a more simplified parameter form of stress-strain expression, and based on the Shen Zhujiang model, a quadratic parabolic form is used to describe the strain, and the model parameter form Improved and established a volume ratio expression reflecting the relationship between soil body strain and axial strain. Finally, the improved model is verified by the test results of coarse-grained soil and cohesive soil. The results show that the theoretical calculation results are in good agreement with the experimental results, and the improved model can better reflect the characteristics of soil body strain and the stress-strain relationship, which provides a reference for the calculation of the soil stress-strain relationship in actual engineering.