扰动作用下类岩石三轴蠕变变形特性试验研究

Study on triaxial creep deformation properties of similar rocks under disturbance

随着我国煤炭开采深度的增加,受扰动影响,巷道围岩变形增大,易导致岩爆、冲击地压等重大灾害,开展受扰动影响的岩石变形特性研究至关重要。文章采用TAW-1000D岩石流变扰动试验仪,对类岩石试件进行三轴蠕变扰动试验,研究不同预静载下扰动荷载对类岩石蠕变变形特性的影响。结果表明:类岩石的极限应变值和长期强度值随着围压的增大而增大;施加扰动荷载后的试件应变值会突变,进入扰动区后,突变值增加较为明显;相同围压下,第一次扰动累计变形值随着预静载的增加而增大,蠕变变形的永久性变形增加;类岩石蠕变扰动破坏表现为斜剪破坏,扰动荷载释放了存储的弹性应变能,造成单元损伤增加,且释放的弹性能超过类岩石单元破坏所需的能量时,类岩石单元发生破坏。

With the increase of coal mining depth in my country,the deformation of the surrounding rock of the roadway affected by the disturbance will increase,which may easily lead to major disasters such as rock bursts and rock bursts.It is very important to study the disturbance and deformation characteristics of the rock.In this paper,the triaxial creep test of rock-like specimens is carried out by TAW-1000D rock creep disturbance tester.The influence of disturbance load on rock creep deformation properties under different static preload is studied.The results show that the ultimate strain value and long-term strength value of rock-like rocks increase with the increase of confining pressure.After the disturbance load is applied,the strain value of the specimen will change suddenly,and after entering the disturbance zone,the sudden change value will increase more obviously.The first cumulative deformation of perturbation augments with the increase of static preload in the same confining pressure.The deformation rate of creep is accelerated by perturbative load and permanent deformation of creep is increased.The damage of rock-like specimen is manifested as oblique shear failure in the condition of creep and perturbation.The perturbation load releases the stored elastic strain energy and causes the element damage to increase.When the released elastic energy exceeds the energy required for the destruction of the rock element,the rock element is destroyed.