围压作用下岩石峰后应力-应变关系模型

发布时间：2018-01-30 03:27

本文关键词： 围压峰后应力-应变强度参数演化 Mohr-Coulomb强度准则　出处：《中南大学学报(自然科学版)》2017年10期 　论文类型：期刊论文

【摘要】：假定峰后软化阶段任意一点皆满足摩尔库仑极限破坏条件,建立岩石峰后后继屈服面模型。利用岩石峰值处和残余阶段初始处应力状态绘制几组莫尔应力圆,获得不同围压下峰值处和残余阶段初始处的黏聚力c和内摩擦角φ,然后分别建立黏聚力c和内摩擦角φ同围压的函数关系。基于莫尔-库仑准则,以最大主应变ε作为软化参数,以分段线性函数形式演化黏聚力c和内摩擦角φ的正切,反求内摩擦角φ,从而建立岩石峰后应力-应变关系模型。数值算例研究Tennessee大理岩三轴试验的峰后应变软化过程,模拟结果与试验结果较吻合。研究结果表明:建立的峰后应力-应变关系模型合理而可靠,可以较好地描述不同围压下岩石的峰后力学行为。
[Abstract]:Assuming that any point in the post-peak softening stage satisfies the limit failure condition of Mohr Coulomb, a yield surface model is established. Several sets of moire stress circles are plotted using the stress state at the peak value and the initial residual stage of the rock. The cohesion force c and the internal friction angle 蠁 at the peak value and the initial residual stage under different confining pressures are obtained, and the functional relationship between the cohesion force c and the internal friction angle 蠁 is established, respectively, based on the Mohr Coulomb criterion. The maximum principal strain 蔚 is used as softening parameter, and the tangent of cohesion force c and internal friction angle 蠁 is obtained in the form of piecewise linear function, and the internal friction angle 蠁 is obtained inversely. The post-peak strain softening process of Tennessee marble is studied by a numerical example. The simulation results are in good agreement with the experimental results. The results show that the established post-peak stress-strain relationship model is reasonable and reliable and can be used to describe the post-peak mechanical behavior of rocks under different confining pressures.
【作者单位】：中南大学资源与安全工程学院;中土集团福州勘察设计研究院有限公司;
【基金】：国家自然科学基金资助项目(11772358) 中南大学硕士生自主探索创新项目(2016zzts448)~~
【分类号】：TU45
【正文快照】： 岩石是矿物的集合体,结构和组成成分复杂,是一种复杂力学性质的材料。其峰后力学特性既是岩石力学研究领域的重点,也是难点之一。刚性试验机的研制,为研究岩石峰后力学行为提供了基础。围岩松动圈理论表明岩体峰后力学特性才是决定巷道稳定性的关键,因此研究岩石的峰后力学行

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