圆板状岩样破坏过程中的渗透特性实验研究

Experimental Research on Permeability of Round Slice Rock Specimen in Its Failure Process

利用一种自行设计的附加渗透试验装置,在MTS815.02岩石力学伺服试验系统上完成了圆板状岩样破坏过程中的渗透特性试验,得到了圆板状岩样渗透率、渗透压差、渗流速度与轴向荷载的关系,并对试验结果进行了分析和讨论。研究表明:1)岩样在渗透的同时发生弯曲变形,岩样的渗透率与其受力状态密切相关,当达到峰值载荷时,渗透率急剧增大,由此验证了突水是伴随着结构破坏的渗流失稳过程;2)岩样在破坏过程中,当轴向载荷达到峰值时,岩样两端压力差急剧减小;3)岩样两端压力差保持0.2MPa,轴向荷载达到峰值时,增压器活塞位移急剧增大,即渗流速度突然变大;4)冲剪破坏为圆板状岩样的主要破坏形式。

Using a self-developed device together with a MTS815.02 Rock Mechanics Servo Test System,permeability experiment of round slice rock specimen in its failure process was carried out,relations among the axial load and the permeability,the seepage pressure and the seepage velocity were obtained.Experimentally obtained parameters were analyzed and discussed.Results show that 1） rock specimen bends during the permeability experiment,and the permeability is closely related with its force-acted state.Permeability increases sharply when load reaches peak value,which validates that water-inrush is seepage instability due to the structure destruction.2） Pressure difference between the upper and lower surface of specimen decreases sharply when load reaches peak value.3） Keeping the pressure difference between the upper and lower surface of specimen around 0.2MPa during the experiment,it is found that the turbocharger piston displacement increases rapidly when the load reaches peak value,that is,the seepage velocity increases suddenly.4） The punching shear is the main failure mode.