粗粒土亚塑性损伤模型

Hypoplasticity damage model of coarse grained soils

为了反映粗粒土主要力学特性,建立了亚塑性损伤模型。结合对粗粒土力学特性及物态演化的认识,提出了粗粒土的损伤状态函数。基于亚塑性理论的基本框架和损伤状态函数,建立了损伤模型的公式及参数确定方法。采用该模型对三峡二期围堰等3种实际工程试验结果进行了模拟。模型预测与试验结果吻合良好。该模型无需判断加卸载准则,易于三维化,公式简洁且参数较少,能够较好地反映粗粒土的主要力学特性,包括强度与围压的非线性特征以及在低围压下剪胀显著、高围压下剪缩较为显著的体变特性。

A new hypoplasticity damage model was developed to characterize the behavior of coarse grained soils. The damage state function was based on the physical state evolution and behavior of the coarse grained soils. The parameters in the hypoplasticity damage model are defined from the fundamental concepts of hypoplasticity theory and the damage state function. The stress-strain relationship responses were predicted for several types of gravel in projects such as the Three Gorges cofferdam. The model predictions agree well with test results. The model has few parameters and a succinct 3-D formula without special loading criterion which can describe the main behavior of coarse grained soils, including the nonlinear relationship between the strength and the confining pressure and the volumetric strain behavior which dilates with low confining pressures but contracts with higher confining pressures.