摘要
采用数值方法模拟硬岩的三轴压缩试验,应用4个本构模型,即Mohr-Coulomb模型、Drucker-Prager模型、应变软化模型及考虑变形模量劣化的应变软化模型,研究中主应力对均质及非均质硬岩破裂机制的影响。结果表明:不论是均质还是非均质岩体,中主应力对采用Drucker-Prager模型的岩体强度影响较大,而对采用其他本构模型的岩体强度影响不大;当非均质岩体采用Mohr-Coulomb模型或Drucker-Prager模型时,中主应力对岩体破坏过程影响不大,但对其破坏模式有较大影响;当非均质岩体采用应变软化模型时,中主应力对岩体破坏过程及其模式均有较大影响。针对工程算例,采用不同的本构模型获得的均质或非均质岩体强度相差很大,除Drucker-Prager模型外,同一本构模型的均质岩体强度远大于非均质岩体。实际工程岩体对中主应力的响应是不同的,故在地下结构设计过程中应根据岩体特性选择合理的本构模型以保证工程安全。
Based on triaxial compressive experiments of hard rock simulated by numerical method, the influence of intermediate principal stress on the fracturing mechanism of homogeneous and heterogeneous rocks is analyzed with four constitutive models, i.e. Mohr-Coulomb, Drucker-Prager and strain-softening considering deformation modulus degradation or not. The results show that the intermediate principal stress has a larger effect on the strength of rock using Drucker-Prager model than that using other models, whether the rock is homogeneous or heterogeneous. And it has a large impact on the failure process and mode of heterogeneous rock using strain-softening model. For the example in this paper, the strength of homogeneous or heterogeneous rock varies considerably with different constitutive models. Although the rock uses the same constitutive model, the strength of homogeneous rock is much larger than that of heterogeneous rock except for Drucker-Prager model. Because the responses of engineering rock masses to the intermediate principal stress are different, proper constitutive model should be chosen based on the characteristics of rock masses in order to guarantee engineering safety during the design process of underground structure.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2013年第5期1469-1477,共9页
Rock and Soil Mechanics
基金
重大水利工程安全性的基础理论研究(No.51021004)
国家创新研究群体科学基金
关键词
岩石力学
中主应力
硬岩
破裂机制
岩石强度
本构模型
非均质
rock mechanics
intermediate principal stress
hard rock
fracture mechanism
rock strength
constitutive model
heterogeneity
