Experimental study on failure mechanical properties of granite with two grain sizes after thermal treatment

被引：0
|
作者：
Yang S.-Q. [1 ,2 ]
Tian W.-L. [2 ]
Dong J.-P. [2 ]
机构：
[1] State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou
[2] School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou
来源：
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | 2021年 / 43卷 / 02期
关键词：
Deformation; Grain size; Granite; High temperature; Rock mechanics; Triaxial strength;
D O I：
10.11779/CJGE202102008
中图分类号：
学科分类号：
摘要：
The grain size has a significant effect on the mechanical behaviors of the thermally treated granite and further affects the safe and stable operation of high level nuclear waste (HLW) repository. Therefore, the granite with two kinds of grain sizes under Brazilian splitting and triaxial compression is adopted to investigate the variation of physical and mechanical parameters with confining pressure and temperature. The results indicate that there are more flaws in the coarse-grained granite than in the fine-grained granite, which results in the less strength and elastic modulus in the coarse-grained granite than those in the fine-grained granite, and the strength and elastic modulus in the coarse-grained granite are more sensitive to the temperature. After the peak strength, the coarse-grained specimens show ductile failure under high confining pressure, and the residual strength increases with the temperature. However, the fine-grained specimens show brittle failure under high confining pressure. On the one hand, micro-cracks are induced by high temperature, which results in the reduction of cohesion among grains. On the other hand, high temperature increases the friction among grains. Therefore, the strength first increases and then decreases with the temperature. The confining pressure can restrain the radial strain and decrease the Poisson's ratio, and partial flaw closure due to the action of confining pressure results in the decrease of the potential of the specimens to adjust when the applied axial compression decreases, which increases the Poisson's ratio. Therefore, the Poisson's ratio of thermally treated granite specimens shows different trends with the confining pressure. © 2021, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.
引用
收藏
页码：281 / 289
页数：8
相关论文
共 20 条
  • [1] ALM O, JAKTLUND L L, SHAOQUAN K., The influence of microcrack density on the elastic and fracture mechanical properties of Stripa granite, Physics of the Earth & Planetary Interiors, 40, 3, pp. 161-179, (1985)
  • [2] XU X L, GAO F, SHEN X M, Et al., Mechanical characteristics and microcosmic mechanisms of granite under temperature loads, Journal of China University of Mining and Technology, 18, 3, pp. 413-417, (2008)
  • [3] XU X L, KANG Z X, JI M, Et al., Research of microcosmic mechanism of brittle-plastic transition for granite under high temperature, Procedia Earth & Planetary Science, 1, 1, pp. 432-437, (2009)
  • [4] SHAO S, WASANTHA P L P, RANJITH P G, Et al., Effect of cooling rate on the mechanical behavior of heated Strathbogie granite with different grain sizes, International Journal of Rock Mechanics and Mining Sciences, 70, pp. 381-387, (2014)
  • [5] SHAO S, RANJITH P G, WASANTHA P L P, Et al., Experimental and numerical studies on the mechanical behaviour of Australian Strathbogie granite at high temperatures: an application to geothermal energy, Geothermics, 54, pp. 96-108, (2015)
  • [6] WAN Zhi-jun, ZHAO Yang-sheng, DONG Fu-ke, Et al., Experimental study on mechanical characteristics of granite under high temperatures and triaxial stresses, Chinese Journal of Rock Mechanics and Engineering, 1, pp. 72-77, (2008)
  • [7] WU Jin-wen, ZHAO Yang-sheng, WAN Zhi-jun, Et al., Experimental study of acoustic emission characteristics of granite thermal cracking under middle-high temperature and triaxial stress, Rock and Soil Mechanics, 30, 11, pp. 3331-3336, (2009)
  • [8] XU Xiao-li, GAO Feng, ZHANG Zhi-zhen, Et al., Energy and structural effects of granite after high temperature, Chinese Journal of Geotechnical Engineering, 36, 5, pp. 961-968, (2014)
  • [9] XU Xiao-li, GAO Feng, ZHANG Zhi-zhen, Research on triaxial compression test of granite after high temperatures, Rock and Soil Mechanics, 35, 11, pp. 3177-3183, (2014)
  • [10] KUMARI W G P, RANJITH P G, PERERA M S A, Et al., Mechanical behaviour of Australian Strathbogie granite under in-situ stress and temperature conditions: An application to geothermal energy extraction, Geothermics, 65, pp. 44-59, (2017)
12