摘要
将浙江龙游石窟的红砂岩加工成含3种排列预制裂纹的圆柱形标准试件,对其进行不同化学溶液、相同流速作用下未受载腐蚀特征试验,获得化学腐蚀损伤时间效应曲线和时效特征。进行不同化学溶液、不同流速作用下裂隙岩石试件的单轴压缩试验,获得裂隙红砂岩的单轴压缩应力–应变曲线,并对其强度变形影响和裂纹搭接破坏模式进行分析。试验结果表明,试件质量的变化与浸泡溶液性质关系不大。溶液pH值最终趋于中性。试件弹性波纵波速最终也趋于稳定。预制裂纹排列方式、浸泡溶液pH值和流速均对岩石力学效应产生较大影响。单轴压缩条件下裂隙红砂岩均为张拉破坏,且其裂纹扩展方向与加载方向一致。裂纹搭接破坏模式主要有拉伸模式与拉伸–剪切模式。浸泡流速和化学溶液对裂纹搭接破坏模式影响不大。该研究为建立应力–水流–化学耦合作用下裂隙岩石破坏过程的本构关系,从而实现对受应力、水流、化学耦合作用的岩石破裂过程模拟和行为预测提供基础。
Rock specimens of red sandstone rocks taken from Longyou Grottoes in China＇s Zhejiang Province are obtained that contain one or two preexisting flaws. Erosive effects of water chemistry of cracked rocks are studied under different chemical solutions and the same velocity. Variations of the mass and wave velocity of the specimens and pH values of solutions with sandstone being soaked are obtained; and the erosion characteristics are analyzed. Based on the results of uniaxial compressive test under different chemical solutions and velocities, the effects of strength and deformation and main modes of crack coalescence are analyzed according to uniaxial compressive stress-strain curves for different cracked rocks under chemical corrosion. The studies indicate that the specimen quality variations have not relations with chemical solutions. The pH value in the chemical solutions ultimately tends to neutral pH, and the elastic wave velocity ultimately almost does not change with time. Preexisting crack arrangement, the pH value and velocity of the chemical solutions all have great influences on the sandstone samples＇ uniaxial compressive strength. Cracked red sandstone sample are tension destruction under uniaxial compression; and the crack propagation direction are consistent with the loading direction. The modes of crack coalescence for specimens containing 1- or 2-flaw are tension and tension-shear modes. Immersion velocity and the chemical solution have not influence on the modes of crack coalescence. The research result provides understanding of the fundamental nature of rock failure and damage mechanics models for simulating nonlinear evolution of tested rock under coupled mechano-hydro-chemical processes.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第4期796-804,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(10472130)
关键词
岩石力学
应力–水流–化学耦合
裂隙岩石
腐蚀特征
单轴压缩试验
应力–应变曲线
rock mechanics
mechano-hydro-chemical coupling process
cracked rocks
erosion characteristic
uniaxial compression test
stress-strain curves
