东北大学学报(自然科学版) ›› 2023, Vol. 44 ›› Issue (3): 415-423.DOI: 10.12068/j.issn.1005-3026.2023.03.015

• 资源与土木工程 • 上一篇    下一篇

基于三轴加卸载试验的花岗岩弹性模量变异与能量演化分析

纪洪广1,2, 陈东升1,2, 苏晓波1,2, 权道路1,2   

  1. (1. 北京科技大学 土木与资源工程学院, 北京100083; 2. 北京科技大学 城市地下空间工程北京市重点实验室, 北京100083)
  • 修回日期:2022-01-14 接受日期:2022-01-14 发布日期:2023-03-24
  • 通讯作者: 纪洪广
  • 作者简介:纪洪广(1963-),男,山东青州人,北京科技大学教授,博士生导师.
  • 基金资助:
    国家重点研发计划项目(2016YFC0600801); 国家自然科学基金资助项目(52074021).

Analysis of Elastic Modulus Variation and Energy Evolution of Granite Based on Triaxial Loading and Unloading Test

JI Hong-guang1,2, CHEN Dong-sheng1,2, SU Xiao-bo1,2, QUAN Dao-lu1,2   

  1. 1. School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China;2.Beijing Key Laboratory of Urban Underground Space Engineering, University of Science and Technology Beijing, Beijing 100083, China.
  • Revised:2022-01-14 Accepted:2022-01-14 Published:2023-03-24
  • Contact: CHEN Dong-sheng
  • About author:-
  • Supported by:
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摘要: 为了研究岩体的变形特征和能量特征与其所处应力状态之间的关系,开展了5种围压下花岗岩的三轴循环加卸载试验.基于应力-应变曲线,计算了循环加卸载过程中花岗岩的弹性模量和能量密度,分析了应力状态对弹性模量及能量演化规律的影响.研究结果表明:轴向弹性模量随围压的增大而增大,随轴向应力的增大先增大后减小.轴向弹性模量与最大、最小主应力呈现良好的二次函数关系.随着围压的增大,能量密度与弹性能占比(弹性能与输入总能量之比)均显著增大,岩石储能能力提高;随着轴向应力增大,弹性能占比先增大后减小.弹性能占比减小阶段即岩石损伤加剧阶段,围压的增加延长了岩石的损伤演化过程.最后讨论了应力状态、岩石力学参数及能量状态的关联性.

关键词: 岩石力学;三轴循环加卸载;弹性模量;能量演化特征;蓄能水平

Abstract: To investigate the relationship between the deformation and energy characteristics of the rock mass and the stress state, triaxial cyclic loading and unloading tests on granite under five types of confining pressure were carried out. Based on the stress-strain curves, the elastic modulus and energy density of the granite were calculated during cyclic loading and unloading, and the influence of the stress state on the evolution of the elastic modulus and energy was analyzed. The results show that the axial modulus of elasticity increases with the increase of the confining pressure, and increases first and then decreases with the increase of the axial stress. The axial modulus of elasticity shows a good quadratic function with the maximum and minimum principal stresses. The energy density and the proportion of elastic energy (the ratio of elastic energy to total energy input) increase significantly as the confining pressure increases, and the energy storage capacity of the rock increases. The proportion of elastic energy increases first and then decreases as the axial stress increases. The decrease in the proportion of elastic energy is the stage of increased damage to the rock, and the increase in the confining pressure prolongs the process of damage evolution. Finally, the correlation between stress state, rock mechanical parameters, and energy state is discussed.

Key words: rock mechanics; triaxial cyclic loading and unloading; elastic modulus; energy evolution characteristics; energy storage levels

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