基于颗粒流程序的黏弹塑性本构模型开发与应用  

Development and application of a visco-elastoplastic constitutive model in particle flow code

作　　者：杨振伟[1] 金爱兵[1] 王凯[1] 孟新秋 高玉娟[2] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]北京大学前沿交叉学科研究院,北京100083

出　　处：《岩土力学》2015年第9期2708-2715,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51074014);中央直属高校基本科研业务费资助项目(No.FRF–SD–12–002A;No.FRF-TP-14-036A1)

摘　　要：在深入研究西原体模型黏弹塑性特征的基础上,推导出不同塑性条件下的流变特性方程,并将其推广到离散单元法中,研究了颗粒间力与位移关系的数值积分方案,总结出颗粒流程序中接触本构模型开发方法,并基于二维颗粒流程序(PFC2D)开发出具有黏弹塑性特征的西原体接触本构模型。通过两个互相接触的固定球体之间的应力松弛试验,分3种情况验证了模型编制的准确性。利用取自张家洼铁矿巷道内的岩石试样,通过单轴和三轴压缩试验获取计算参数,并进行了单轴压缩蠕变试验的模拟,通过与室内蠕变试验结果的对比,验证了PFC2D中自定义西原体模型用于岩石流变特性研究的可行性。利用西原体模型与线弹性模型对D型深埋巷道进行分析计算和破坏模式研究,结果显示,西原体模型预测结果与Hoek-Brown准则理论结果更为接近。在围岩蠕变作用下,巷道两帮变形量大于顶板和底板,破坏程度更为严重,计算结果与现场监测数据基本吻合。根据巷道长期稳定性的要求,提出着重支护两帮的治理建议。In this paper, theological equations at different plastic conditions are derived on the basis of visco-elastoplastic Nishihara model, and then these equations are further implemented into discrete element method. By studying the numerical integral scheme of force-displacement relationship between particles, the methods for developing contact constitutive model in Particle Flow Code （PFC） are summarized. Thus a user defined viseo-elastoplastic Nishihara contact constitutive model is proposed under PFC in 2 dimensions （PFC^2D）.,Through stress relaxation experiments between two fixed balls, the accuracy of the developed model is verified for three cases. Numerical parameters are obtained by the uniaxial and triaxial compression experiments on rock specimens from underground roadway in Zhangjiawa Iron Mine, and then it is applied to simulate the uniaxial compressive creep experiment. The feasibility of Nishihara model in PFC2D for rock theological properties is proved by comparing the results with experimental data, and then failure modes of a D-shaped roadway are investigated using Nishihara model and a linear-elastic model. Numerical results of Nishihara model are in good agreement with the theoretical result of Hoek-Brown strength criterion. The deformations of two sides are substantially greater than those of the top and bottom and the corresponding failures of two sides are more serious due to the creeping of wall rock. Numerical results, to large extent, agree with the field monitoring data. It is suggested that the support on both sides should be greatly strengthened for satisfying requirements of long-term stability.

关 键 词：蠕变试验 颗粒流程序 西原体流变模型 黏弹塑性 流变特性 巷道蠕变 

分 类 号：TU452[建筑科学—岩土工程]