不同初始蓄能的梯度加载岩爆模型试验

Model Tests on Rock Burst Using Gradient Loading under Different Initial Energy Storage Conditions

为了探讨不同类型围岩储存能量特性对岩爆的影响,应用气液复合加载岩爆模型试验装置,采用0 MPa、2 MPa、3 MPa三种初始蓄能气压模拟不同类型围岩储存能量特性,进行了梯度加载岩爆模型对比试验,对试件宏观破坏特征、内部应力和破坏瞬间的应变特性及声发射特征参数进行了系统的研究。结果表明:通过气液复合加载器蓄能腔中不同初始蓄能气压大小的设置可以达到定性模拟不同类型围岩储存能量特性对岩爆的影响分析,初始蓄能气压越大(围岩储存能量能力越强),试件破坏瞬间的应变越大,卸载面应力集中程度越高,破坏历时越短,能量释放的速率越快,岩爆破坏越显著;气液复合加载较液压加载,对于岩爆现象的发生及烈度有促进作用。

In order to explore the effect of different types of energy storage characteristics of surrounding rock on rockburst,a rockburst model test device combined with gas-liquid composite loading was designed to compare the gradient loading rockburst model under different initial energy storage gas pressure of 0 MPa,2 MPa and 3 MPa respectively.The macroscopic damage characteristics,internal stress,strain features at the moment of destruction and acoustic emission characteristics parameters of specimens were analyzed systematically.The results show that the different initial energy storage gas pressures in the accumulating cavity of gas-liquid combined loader can qualitatively simulate the influences of different energy storage characteristics of surrounding rock on rockburst.The greater the initial gas pressure in the energy storage chamber of the gas-liquid composite loader,the greater the strain at the moment of destruction and the higher stress concentration on the unloading surface.Moerover,the shorter the duration of destruction,the faster the release rate of energy and also the more significant the rockburst damage.Compared with hydraulic loading,the gas-liquid composite loading can promote the occurrence and intensity of the rockburst phenomenon.