长江科学院院报 ›› 2019, Vol. 36 ›› Issue (2): 71-76.DOI: 10.11988/ckyyb.20170645

• 岩土工程 • 上一篇    下一篇

原始损伤性片麻岩变形破坏中的能量特征分析

冯伟,邓荣贵,王拓,陈拔进   

  1. 西南交通大学 土木工程学院,成都 610031
  • 收稿日期:2017-06-05 修回日期:2017-08-03 出版日期:2019-02-01 发布日期:2019-03-11
  • 作者简介:冯 伟(1992-),男,江苏常州人,硕士研究生,主要从事工程地质、隧道方面的研究。E-mail: 594420749@qq.com
  • 基金资助:
    国家自然科学基金项目(41272321)

Energy Properties of Original Damaged Gneiss During Deformation Failure

FENG Wei, DENG Rong-gui, WANG Tuo, CHEN Ba-jin   

  1. School of Civil Engineering, Southwest Jiaotong University,Chengdu 610031, China
  • Received:2017-06-05 Revised:2017-08-03 Online:2019-02-01 Published:2019-03-11

摘要: 为探究不同初始损伤状态片麻岩在载荷作用下能量变化特征,取某隧道工程岩样进行单轴试验和三轴试验。对各试验岩样的应力-应变曲线特征进行分析,并对能量随应变的演化规律进行研究,结果表明:原地应力环境对试件性质影响较大;三轴试验条件下,岩石的能量演化规律可分为3个阶段,即稳定二次增长阶段、稳定破裂阶段及加速破裂阶段;损伤程度较高的片麻岩弹性能储存能力较弱,峰前扩容更明显,破裂位置更多;裂隙压密岩石弹性能储存比例高,脆性破坏更明显;卸围压过程中整体能量释放速率大于理论弹性能释放速率时,将造成卸荷损伤,使得岩石强度降低。该研究丰富了损伤性岩体的能量演化特征认识,并为片麻岩岩体工程建设提供了新的分析思路。

关键词: 片麻岩, 弹性能, 能量耗散, 单轴试验, 三轴试验, 损伤程度

Abstract: In an attempt to investigate the energy variation properties of gneiss under different initial fracture states, uniaxial and triaxial tests were designed and conducted on rock specimens from a tunnel project. By analyzing the stress-strain curves of test specimens, the evolution of energy with strain was obtained. Results show that in-situ stress environment has great influence on the properties of rock specimens. The energy evolution rule of gneiss can be divided into three stages in triaxial test: secondary steady growth stage, stable fracture stage, and accelerated fracture stage. Gneiss of high damage degree is of weak ability to restore elastic energy.The expansion of gneiss is more obvious and fracture occurs at more positions. Fractured compacted rock stores higher proportion of elastic energy, with more apparent brittle failure. If the practical energy release rate is higher than theoretical elastic energy release rate under confining pressure unloading, damage will be produced to weaken the strength of rock.This study enriches the cognition of energy evolution of damaged rock mass and provides a new idea for the construction in gneiss engineering.

Key words: gneiss, elastic energy, energy dissipation, uniaxial test, triaxial test, damage degree

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