Abstract:In recent years,issues of rock mechanics under high temperature have been highlighted with the rapid development of nuclear waste treatment and underground coal gasification projects,which has become a focus in the rock mechanics field currently. In order to investigate the influence of temperature and sample size on the tensile strength,Brazilian splitting tensile strength tests were conducted on sandstone disc samples with five kinds of temperature levels ranging from 20 ℃ to 800 ℃ and five kinds of thickness-diameter ratios ranging from 0.5 to 1.0. Experimental results show that loading-displacement curves of sandstone discs appear remarkable brittle characteristics. And the temperature plays a leading role in the development trend of the curves,while the effect of sample size is relatively weak. With the increase of temperature,tensile strength first increases gradually and then decreases sharply,and reaches the maximum at 400 ℃. The tensile strength of sandstones under same temperature presents a linear attenuation relationship with the thickness-diameter ratio,and the corresponding experiential formula is put forward as ?t =-Aλ + B. Here,the parameter A describes the prominent level of materials affected by the size,which decreases first and then increases with the increase of temperature,and the size effect is mostly unconspicuous at 400 ℃. The parameter B is the tensile strength value of materials when the sample size is infinitesimal to the ideal plane,which first increases slowly and then decreases gradually,with the maximum value also reaches at 400 ℃.
苏海健,靖洪文,赵洪辉,尹 乾. 高温处理后红砂岩抗拉强度及其尺寸效应研究[J]. 岩石力学与工程学报, 2015, 34(s1): 2879-2887.
SU Haijian,JING Hongwen,ZHAO Honghui,YIN Qian. STUDY ON TENSILE STRENGTH AND SIZE EFFECT OF RED SANDSTONE AFTER HIGH TEMPERATURE TREATMENT. , 2015, 34(s1): 2879-2887.
刘宝琛,张寄生,杜奇中,等. 岩石抗压强度的尺寸效应[J]. 岩石力学与工程学报,1998,17(6):611-614.(LIU Baochen,ZHANG Jisheng,DU Qizhong,et al. A study of size effect for compression strength of rock[J]. Chinese Journal of Rock Mechanics and Engineering,1998,17(6):611-614.(in Chinese))
[2]
张 明,卢裕杰,杨 强. 准脆性材料的破坏概率与强度尺寸效应[J]. 岩石力学与工程学报,2010,29(9):1 782-1 789.(ZHANG Ming,LU Yujie,YANG Qiang. Failure probability and strength size effect of quasi-brittle materials[J]. Chinese Journal of Rock Mechanics and Engineering,2010,29(9):1 782-1 789.(in Chinese))
Your browse does not support frame!