摘要
为探讨饱水作用对巴东组泥岩的强度参数与变形特性及其能量演化的影响规律,进而建立力学特性、能量演化以及微裂纹发育三者间的内在联系,首先开展天然与饱和状态下泥岩的单轴压缩试验,采用应变曲线法确定特征强度,定量比较分析泥岩特征强度的劣化规律和能量参数的数值差异,深入挖掘泥岩水岩作用过程中的能量转化特征,据此给出泥岩饱水软化机制的能量解释。试验发现饱水作用对泥岩力学特性的影响表现为特征强度降低、脆性变形减弱、塑性变形增强、各变形段差异明显,对泥岩能量演化的影响表现为饱水后岩石吸能与释能性质减弱、耗能性质增强、各段的能量分配规律不同。随后,基于试验数据依托颗粒流软件虚拟实现同等条件下的数值试验,分析模拟试样微裂纹发育特征与能量演化的相互影响和相互作用,揭示泥岩能量演化的微细观机制。结果表明颗粒流理论在从细观力学角度解释岩石损伤破坏机制方面具有优越性,为岩石非均质特性的微细观研究提供了新的手段。
In order to study the influence of water saturation on the strength parameters,deformation characteristics and energy evolution of Badong formation mudstone as well as the internal relation among the mechanical properties,energy evolution and microcrack development,uniaxial compression tests of mudstone under natural and saturated states are carried out,and the characteristic strength is determined by strain curve method.Through the quantitative comparative analysis of the deterioration law of the characteristic strength and the numerical difference of energy parameters as well as in-depth exploration of energy transformation characteristics in the process of water-rock interaction,the energy explanation of mudstone saturation softening mechanism is given.It is found that the effect of saturation on the mechanical properties of mudstone is manifested by reduction of the characteristic strength,weakening of the brittle deformation,enhancement of the plastic deformation and difference among deformation stages.Meanwhile,the influence of saturation on the energy evolution presents weakening of energy absorption and release properties,enhancement of energy dissipation properties and different energy distribution rules of each stage after saturation.On the basis of the experimental data,the numerical compression tests under the same water conditions are performed by means of particle flow code software,and the interaction between the development characteristics of micro-cracks and energy evolution of samples is analyzed to reveal the micro-mechanism of mudstone energy evolution.The results show that the particle flow theory is superior in explaining the damage mechanism of rocks from the perspective of meso-mechanics and provides a new means for the micro-study of rock heterogeneity.
作者
柳万里
晏鄂川
戴航
杜毅
肖炜波
赵松
LIU Wanli;YAN Echuan;DAI Hang;DU Yi;XIAO Weibo;ZHAO Song(Faculty of Engineering,China University of Geosciences,Wuhan,Hubei 430074,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2020年第2期311-326,共16页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41672313,41702378,41807240)。
关键词
岩石力学
巴东组
水作用
特征强度
能量演化
细观力学机制
rock mechanics
Badong formation
water effect
characteristic strength
energy evolution
micromechanical mechanism
