摘要
对小尺寸效应下黄砂岩的力学特性和声学特征进行研究,探讨小尺度效应下岩石强度、变形、弹性常数(弹性模量、泊松比)、破坏形态及能量转化的规律,分析声发射能量、计数和峰频与尺寸之间联系,得到如下结论:随着尺寸的增加,强度呈现线性递减,径向应变从斜落向水平方向延伸且呈现先减小后平稳的趋势,轴向应变逐渐减小,体应变呈现先增长后稳定再递减的趋势,破裂范围逐渐减小,剪切角度呈现先减小后增大的趋势,弹性模量和泊松比呈现增长的趋势,峰后的能量呈现先加速后稳定再减速的释放规律;随着尺寸的减小,耗散能和峰前积聚的总能量均呈现增大的趋势;耗散能加速阶段和减速阶段逐渐递减,稳定阶段逐渐延长;能量之间呈现“闭口”的趋势;弹性能、释放能及盈余能量均呈现递减的趋势;声发射能量与时间呈现“双峰”现象,声发射计数与能量呈现“喇叭式”扩延,同时出现高能、高计、高峰(三高)时可以预判岩石即将发生破坏;随着尺寸的减小,计数峰值区间滞后出现。声发射的总能量与尺寸呈现正比例关系。声发射峰频呈现明显的分区特性。
The mechanical and acoustic characteristics of yellow sandstone under small-size effect were studied. The rock strength,deformation,elastic constants(elastic modulus,Poisson’s ratio),failure morphology and energy conversion law under small-size effect were discussed. The relationships between the acoustic emission energy,the count,the peak frequency and the size were analyzed. As the size increases,the strength decreases linearly,and the radial strain extends from the oblique to the horizontal direction and exhibits a tendency to decrease first and then to stabilize,and the axial strain gradually reduces. Body strain increases first,then stabilizing and then decreasing. The rupture range decreases gradually. The shear angle decreases first and then increases. The elastic modulus and Poisson’s ratio show an increasing trend. The energy after the peak shows a release law of accelerating first,then stabilizing and then decreasing. With the decrease of size,the dissipated energy and the total energy accumulated before the peak show an increasing trend,the dissipative energy acceleration phase and the deceleration phase are gradually decreasing,and the stabilization phase is gradually extended. There is a tendency of "closed-cup" between energy,elastic energy,release energy and surplus energy all show a decreasing trend,acoustic emission energy and time show a"double peak"image. The emission count and energy show"horn" expansion,while high energy,high meter,high peak(three high) can predict the impending destruction of the rock;as the size decreases,the total energy of the acoustic emission appears after the peak interval is counted. The total energy of the acoustic emission is proportional to the size. The characteristics of acoustic emission peak frequency is obvious partitioning.
作者
刘刚
肖福坤
秦涛
LIU Gang;XIAO Fukun;QIN Tao(Heilongjiang Ground Pressure and Gas Control in Deep Mining Key Laboratory,Heilongjiang University of Science and Technology,Haerbin,Heilongjiang 150022,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第A02期3905-3917,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51574115,51604100)
哈尔滨市科技局科技创新人才研究专项资金项目(2017RAQXJ041)~~
关键词
岩石力学
小尺寸
能量转化
力学特性
声学特征
rock mechanics
small size
energy conversion
mechanical properties
acoustic characteristics
