不同卸荷速率条件下岩爆碎屑破坏特征分析

摘要

To study the influence of unloading rate on the rock burst,the rock burst tests of marble under different unloading rates were conducted by using the rock true triaxial servo mutation (disturbance) test system,and thc fragments produced in the tests were collected.The scale characteristics of the fragments and the distribution characteristics of different particle size and mass were obtained through the measurement of mass,particle size and basic scale of the fragments,and the fractal characteristics of the obtained fragments were studied.The results showed that in the process of rock burst,a lot of fractured fragments with the massive,tabular,sheet and laminar shapes col-lapsed to the free face carrying a large amount of kinetic energy which transformed from the energy stored by the rock itself.The unloading rate had a direct influence on the severity of rock burst,and the faster the unloading rate,the more intense the rock burst.%为研究卸荷速率对岩爆的影响,采用岩石真三轴伺服诱变试验系统对大理岩进行不同卸荷速率下的岩爆试验,收集试验后得到的碎屑.通过对碎屑质量、粒径以及基本尺度的测量,得到碎屑的尺度特征以及不同粒径质量的分布特征;同时对所得到的碎屑进行分形特征研究.结果表明:在岩爆过程中,存在大量破碎的块状、板状、片状以及薄片状碎屑携带大量动能向临空面崩落,其携带的动能是由岩体自身储存的能量转化而来;卸载速率对岩爆的剧烈程度有着直接的影响,卸荷速率越快,发生岩爆时其程度越剧烈.