加载速率效应下圆形硐室岩爆特征模拟试验研究

利用RLW-3000伺服岩石力学试验系统,对深部高应力条件下的圆形硐室岩爆过程进行室内双轴加载模拟试验研究。通过研究不同加载速率条件下试样破坏的声发射时序特征,并结合其力学特性和宏观现象。研究结果表明:随着加载速率的增大,岩屑开始弹射时的荷载有明显的下降趋势,同时岩屑开始弹射时的时间也明显提前;模拟圆形硐室两侧岩爆的开始时间、剧烈程度有明显差别,这可能是试样的应力集中位置改变引起的,应力集中位置改变的原因可能是试样的离散性、加载偏心等,这些尚需要进一步的试验来验证;加载速率会影响岩爆的孕育时间、剧烈程度。速率越大岩爆的孕育时间越短,同时岩爆也越剧烈,且岩爆时声发射的振铃计数率、累计振铃计数、能率、累计能量陡增点越提前,最大值也越大。研究内容对研究岩爆过程中加载速率的作用具有重要意义,同时为预防岩爆发生提供一定的借鉴。

Simulation test study on rock burst characteristics of circular chamber under loading rate effect

In this paper, the RLW-3000 servo rock mechanics test system is used to study the rockburst process of circular chamber under deep high stress. By studying the characteristics of acoustic emission timing under different loading rate, combined with its mechanical properties and macroscopic phenomena. The results show that with the increase of loading rate, the load of cuttings begins to show a significant decrease, and the time when the cuttings begin to ejection is obviously ahead of time. The start time of rockburst on both sides of the circular chamber is simulated, There is a significant difference in the severity of the stress, which may be caused by the change of the stress concentration position of the specimen. The reason for the change of the stress concentration position may be the discretization of the specimen, the eccentricity of the loading, etc., which still need further test to verify; the loading rate will affect Rock burst time, severity. The greater the rate of rock burst the shorter the breeding time, while the rock burst is also more intense, and the rock burst when the sound ringing count rate, the cumulative ringing count, the rate, the cumulative energy steep point in advance, the greater the maximum. The research contents are of great significance to study the effect of loading rate in rockburst process, and provide some reference for the prevention of rockburst.