Experimental Study on the Influence of Joint Fillers on the Crack Initiation Strength of Rock Masses
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摘要: 以水泥、泥浆、石膏三种材料作为填充物制作含单一裂纹的节理岩体试件,进行单轴压缩试验,并通过建立单轴压缩下闭合裂纹起裂强度的解析表达式和开展数值模拟对其进行深入的研究。研究表明:在单轴压缩下,基于摩擦系数理论数值模拟得到的试件起裂强度与室内试验测得的峰值强度基本吻合;填充物摩擦系数越大,节理岩体越难被破坏,且与无填充岩体相比含填充岩体的起裂强度大幅提高;含填充节理试件的峰值强度远大于无填充的节理试件,其中填充水泥的节理试件峰值强度最高,填充泥浆的最低;剪切破坏是泥浆作为填充物的试件的主要破坏形式,而水泥和石膏作为填充物的试件的破坏则是复合型;随着填充物强度的提高,节理岩体的破坏形式将从剪切破坏转变为张拉破坏。Abstract: Three kinds of materials—cement, mud and gypsum, were used as fillers to fill jointed rock specimens with single crack, and uniaxial compression tests were conducted on the specimens. The analytical expression about initiation strength of crack for closed crack under uniaxial compression was established and numerical simulations were performed to further study it. The results showed that under uniaxial compression, the initiation strength of crack for specimens simulated by the friction coefficient theory was basically consistent with the peak strength from indoor tests. The larger the friction coefficients of fillers were, the less easier the damage of jointed rock masses, and the initiation strength of crack for rock masses with fillers was greatly improved than that without fillers. The peak strength of cement-filled jointed specimens was highest and mud-filled jointed specimens was lowest. Shear failure was the main failure mode of specimens filled with mud, the failure form of specimens filled with cement and gypsum was complex. With the increase of filler strength, the failure mode of jointed rock mass would change from shear failure to tension failure.
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Key words:
- filler /
- closed crack /
- friction coefficient /
- indoor test /
- initiation strength of crack
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