| 摘要: |
| 对韩城地区3＃和5＃煤岩在9MPa围压下进行三轴蠕变试验,通过分级加载试验获取不同应力水平下煤岩的蠕变曲线。建立不同应力水平下煤岩的蠕变本构方程,并根据试验数据进行参数识别。结果表明:当3＃和5＃煤岩样的轴向应力分别小于其瞬时抗压强度的60％、40％时,蠕变曲线仅包含瞬时变形阶段、衰减蠕变阶段和等速蠕变阶段,在等速蠕变阶段应变速率几乎为零;当3＃和5＃煤岩样的轴向应力分别介于其瞬时抗压强度的60％ ～ 80％、40％ ～ 80％时,等速蠕变阶段的应变速率近似为一常值;而当3＃及5＃煤岩样的轴向应力均为其瞬时抗压强度的80％以上,蠕变试验曲线分别表现出蠕变脆性破坏特性和蠕变韧-脆性破坏特性。 |
| 关键词: 煤岩 三轴蠕变试验 本构方程 |
| DOI：10.3969/j.issn.1673-5005.2013.04.023 |
| 分类号::TU 451 |
| 基金项目:国家科技重大专项(2011ZX05038-004) |
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| Creep and damage characteristics of coal rock under different stresses |
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ZHAO Bin, WANG Zhi-yin, WU Jin-peng
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(Beijing Key Laboratory of Urban Oil and Gas Distribution Technology in China University of Petroleum, Beijing 102249, China)
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| Abstract: |
| Creep curves of coal rock specimens 3＃ and 5＃from Hancheng area were obtained by triaxial creep test under 9MPa confining pressure through multi-stage loading. Creep constitutive equations under different stress level were established on the basis of the rheological theory of rock and data of creep tests, and the parameters in constitutive equations were identified through test data. The results show that the creep curves of coal rock specimens 3＃ and 5＃are composed of instantaneous deformation stage, decay creep stage and stable creep stage. While differential stresses are less than 60％ and 40％ of the corresponding instantaneous compressive strength, respectively. The strain rate is nearly zero in the stable creep stage. While differential stresses are 60％-80％ and 40％-80％ of the corresponding instantaneous compressive strength, respectively, the strain rate is a constant in the stable creep stage. The creep curves of 3＃and 5＃coal rock specimen show the characteristics of brittle failure and toughness-brittle failure respectively while the differential stresses are above 80％ of its instantaneous compressive strength. |
| Key words: coal rock triaxial creep test constitutive equation |
