Experimental Study on Acoustic Emission of Coal and Rock underSeepage-creep Coupling Action
-
摘要: 为研究煤岩在渗流—蠕变耦合作用下的声发射及损伤特性，进行了4组不同渗透水压和围压的蠕变声发射测试实验。研究结果表明：累计渗流量曲线对应于蠕变应变曲线，可分为初始、稳态、加速3个阶段；受渗流和蠕变作用的相互影响，在相同围压下，渗透压越大，煤岩的瞬时应变量越大，蠕变速率越高，渗流量越大，声发射越活跃；在相同渗透压下，围压越大，煤岩的瞬时应变量越小，蠕变速率越低，渗流量越小，声发射活跃程度降低；声发射在渗流—蠕变全过程中，整体呈U型变化特征，在体积压缩向体积扩容转变期，声发射异常活跃，表明煤岩此时处于内部结构的调整和损伤状态的转变期；基于Weibull分布函数的损伤表明，各围压下煤岩均存在一个损伤阈值，当损伤超过此值时，煤岩进入加速蠕变变形阶段，且损伤阈值有随围压升高而增大的趋势。Abstract: In order to explore the acoustic emission and damage characteristics of coal and rock under seepage-crreep coupling action, creep acoustic emission tests were carried out with four different groups of seepage pressure and confining pressure. The research results showed that the cumulative flow curves corresponded to the creep curves and can be divided into three stages of the initial, steady state and acceleration; affected by the mutual influence of the seepage and creep action and under the same confining pressure, the greater the seepage pressure of coal and rock, the greater the instantaneous strain of them, the higher the creep rate, the greater the amount of seepage and the more active the acoustic emission; under the same seepage pressure, the greater the confining pressure, the smaller the instantaneous strain of coal and rock, the lower the creep rate, the smaller the amount of seepage and the active degree of the acoustic emission decreased; in the seepage-creep process, the acoustic emission presented an overall U-shaped change, the volume compression was transformed to the volume expansion period, the acoustic emission was extremely active, this indicated that the coal and rock were in a transition period of their internal structure adjustment and damage state at this time; the damage based on the Weibull distribution function indicated that the coal and rock were all had a damage threshold value under different confining pressures, and when the damage exceeded this threshold value, the coal and rock entered the accelerated creeping deformation stage, and the damage threshold value tended to increase with the increase of the confining pressure.
-
Keywords:
- coal and rock /
- seepage-creep coupling /
- acoustic emission /
- damage /
- threshold value
-
-
[1] 吴立新,王金庄.煤岩流变特性及其微观影响特征初探[J].岩石力学与工程学报,1996,15(4):328-332. [2] 何峰,王来贵,王振伟,等.煤岩蠕变-渗流耦合规律实验研究[J].煤炭学报, 2011,36(6):930-933. [3] 何峰,臧立岩,张建生,等.煤岩体蠕变-渗流耦合数值模拟[J].辽宁工程技术大学学报(自然科学版),2011, 30(6):806-809. [4] 何峰,李彬,王振伟,等.煤岩渗流-蠕变耦合试验研究[J].金属矿山, 2016(8):63-68. [5] 王登科,彭明,魏建平,等.煤岩三轴蠕变-渗流-吸附解吸实验装置的研制及应用[J].煤炭学报, 2016,41(3):644-652. [6] 尹光志,蒋长宝,许江,等.含瓦斯煤热流固耦合渗流实验研究[J].煤炭学报, 2011, 36(9):1495-1500. [7] 杨永杰,陈绍杰,韩国栋.煤岩压缩破坏过程的声发射试验[J].煤炭学报,2006,31(5):562-565. [8] 李玉寿,杨永杰,杨圣奇,等.三轴及孔隙水作用下煤的变形和声发射特性[J].北京科技大学学报, 2011, 33(6):658-663. [9] 夏冬,杨天鸿,常宏.含水煤岩损伤破坏过程中声发射特征的研究[J].金属矿山, 2014, 43(6):1-9. [10] 高保彬,李回贵,李化敏,等.含水煤样破裂过程中的声发射及分形特性研究[J].采矿与安全工程学报, 2015, 32(4):665-670. [11] 左建平,裴建良,刘建锋,等.煤岩体破裂过程中声发射行为及时空演化机制[J].岩石力学与工程学报, 2011, 30(8):1564-1570. [12] 杨永杰,王德超,赵南南,等.煤岩蠕变声发射特征试验研究[J].应用基础与工程科学学报, 2013, 21(1):159-166. [13] 曹树刚,刘延保,张立强,等.突出煤体单轴压缩和蠕变状态下的声发射对比试验[J].煤炭学报, 2007, 32(12):1264-1268. [14] 工程岩体试验方法标准:GB/T 50266-2013[S]. [15] 曹亚军,王伟,徐卫亚,等.低渗透岩石流变过程渗透演化规律试验研究[J].岩石力学与工程学报, 2015,34(S2):3822-3829. [16] HEIPLE C R, CARPENTER S H.Acoustic Emission from Dislocation Motion[M].In:Acoustic Emission, New York:Gordon and Breach Science Publishers, 1983.
[17] WADLEY H N G, SCRUBY C B, SPEAKE J H. Acoustic emission for physical examination of metals[J]. International Metals Reviews, 1980, 25(1):41-64.
[18] 唐春安.岩石破裂过程中的灾变[M].北京:煤炭工业出版社,1993.
计量
- 文章访问数: 23
- HTML全文浏览量: 0
- PDF下载量: 3
下载:
