改进的Bingham岩石蠕变模型研究

Studies on Improved Bingham Rock Creep Model

传统Bingham模型只能模拟岩石的瞬时弹性变形和稳态蠕变变形,不能模拟岩石蠕变全过程。为了克服这方面的不足,首先定义一个非线性函数来模拟岩石的衰减蠕变变形,基于Harris函数建立一个带时间触发的非线性损伤黏性体,与传统Bingham模型进行串联,从而建立一个新的非线性蠕变模型,根据塑性力学原理推导了一维和三维蠕变方程。利用1stOpt通用的全局优化算法,对前人所做的蠕变试验数据进行模型验证和参数辨识,同时基于理论曲线对模型参数进行敏感性分析。结果表明,该模型曲线与蠕变试验曲线具有较高的吻合度,在相同时刻,岩石蠕变变形量均随参数的增大而增大;模型曲线对参数n的敏感性要高于对参数m。该模型可为开展类似研究工作提供一定的参考。

Merely capable of simulating the instantaneous elastic deformation and steady-state creep deformation of rock,traditional Bingham model cannot simulate the whole process of rock creep.To overcome this deficiency,a nonlinear function was first defined to simulate the decay creep deformation of rock,and then a time-triggered non-linear damage viscous body was established based on Harris function and connected in series with the traditional Bingham model to develop a new non-linear creep model.One-dimensional and three-dimensional creep equations were derived according to the principles of plastic mechanics.Then,model verification and parameter identification on existing creep experimental data were performed using 1 stOpt universal global optimization algorithm,and sensitivity analysis on the parameters in the model was conducted.The results show that the model curve is in good agreement with the creep test curve.At the same instance,the rock creep deformation increased as the parameters became larger;and the model curve was more sensitive to parameter n than parameter m.The proposed model can provide reference for relevant future researches.