摘要
利用三维数字图像相关技术(3D-DIC)观测系统研究单轴压缩状态下带中心圆孔花岗岩岩板的破坏全过程,得到了含孔洞岩石破坏过程中观测面的三维全场位移和应变,不仅能够直观地反映岩石表面裂隙的产生、扩展及相互连通的演化过程,亦能够确定裂纹的位置、形态以及扩展方向等具体信息,还能重现加载过程中试样表面的压缩(平行荷载方向)、剥离(垂直荷载方向)、膨胀及剥落(垂直试样表面方向)。结果表明:3D-DIC技术在岩土力学试验中有其独特的优势,岩石材料破坏过程中应变场的演化能较好地反映其内部裂纹的产生和扩展规律。根据全场应变云图可以判断岩石裂纹扩展演化的情况;裂纹的演化具有强烈的非线性特征,在试样接近破坏时形成的"X"型对称变形局部化带,最终只形成一条宏观破坏带,荷载方向、岩石结构及其内部的非均匀性都会对最终宏观破裂带的位置产生影响;利用3D-DIC观测系统进行岩石变形破坏机制的研究是有效的,可为岩土介质宏细观变形破坏机制的研究提供重要的借鉴。
The failure process of granite plate with a hole at its center is examed under uniaxil compression using three-dimensional digital image correlation （3D-DIC） technique. The obtained evolutions of displacement field and strain field not only reflect the basic law of internal crack initiation and propagation but also reproduce the compression （parallel to the loading direction）, stripping （vertical to the loading direction）, expansion and spalling （vertical to the specimen surface） of the observation surface. The main findings are： 3D-DIC technique demonstrates its unique advantage in geotechnical experiments. The evolution of strain field during rock destruction is able to reflect the basic law of crack initiation and propagation which in turn can be observed by analyzing full strain contours. The evolution of crack is characterized with nonlinearity. The X-shaped local failure bands, forming slightly before rock destruction, eventually evolve into a macro-destruction zone, whose location is collectivelly controlled by the direction of load, the structure and interior heterogeneity of rock. It is effective to study the mechanism of rock deformation by using 3D-DIC technique, which can provide an important reference for the research on the macroscopic and mesoscpic.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第1期117-123,共7页
Rock and Soil Mechanics
基金
国家重点基础研究发展计划资助(No.2015CB057902
No.2015CB057906)~~
关键词
三维数字图像相关技术:带孔岩板
非接触
全场应变测量
裂纹扩展
破坏
three-dimensional digital image correlation （3D-DIC）
rock plate with hole
non-contact
full-field strain measurement
crack propagation
failure
