基于改进Bingham模型的软岩参数非定常三维非线性黏弹塑性蠕变本构研究  

Study on 3D nonlinear visco-elastic-plastic creep constitutive model with parameter unsteady of soft rock based on improved Bingham model

作　　者：刘开云[1] 薛永涛 周辉[3] LIU Kai-yun;XUE Yong-tao;ZHOU Hui(School of Civil Engineering,Beijing Jiaotong University,Beijing,100044;Henan Provincial Communications Planning ＆ Design Institute Co.,Ltd.,Zhengzhou,Henan 450000,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]河南省交通规划设计研究院股份有限公司,河南郑州450000 [3]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩土力学》2018年第11期4157-4164,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目资助(No.51378052)~~

摘　　要：传统线性元件组合模型难以描述岩石非线性加速蠕变阶段特性,给工程应用带来了巨大困难。提出一种新的应变触发非线性黏壶元件,并将其与Bingham模型串联,建立了可以描述岩石等速和加速蠕变特性的一维本构模型,进而推导出相应的三维蠕变本构模型,再将三轴压缩过程中岩石弹性模量的衰减方程引入该三维蠕变本构方程,得到一个能反映岩石蠕变全过程特性的三维非线性黏弹塑蠕变本构模型,根据泥岩蠕变试验数据对该模型参数进行了辨识。模型理论计算值与泥岩蠕变试验数据的对比表明改进的Bingham模型不仅可以充分反映软岩的等速蠕变特性,还可以很好地描述软岩的衰减和加速蠕变规律,且模型元件少,组合形式简单,为软岩非线性蠕变本构模型研究提供了新的借鉴。The characteristics of the nonlinear accelerated creep stage of rock cannot be represented by the traditional model combined by the linear element, which brings great challenges to engineering applications. We proposed a new nonlinear viscous dashpot element with a strain trigger which was further connected with the Bingham model to form a new one-dimensional（1 D） constitutive model. The newly established model can represent the constant and accelerated creep characteristics of rock, and the corresponding 3 D constitutive equation was deduced in detail. Then, the attenuation law of the elastic modulus during the triaxial compression process was introduced into the 3 D creep constitutive equation to obtain 1 D nonlinear creep constitutive model which can reflect the whole process curve of rock creep. The model parameters were identified by the triaxial compression creep experimental data of mudstone. From the comparison of results calculated by this model and experiments, it can be concluded that the improved Bingham model not only can describe preciously the three creep phases including deceleration creep, stable creep and acceleration creep of soft rock, but also has the advantages of few components and simple combination form. This study provides a new study reference for the nonlinear creep constitutive model of soft rock.

关 键 词：软岩 蠕变 非定常 非线性 黏弹塑本构 

分 类 号：O344.6[理学—固体力学]