动态孔隙水作用下砂岩力学特性试验研究

Experimental Study of Mechanical Properties of Sandstone Under a Dynamic Pore Pressure

为研究动态孔隙水作用下砂岩的力学特性,采用MTS815.02型电液伺服岩石力学试验系统和PCI-2声发射测试系统,对砂岩进行不同孔隙水压下的三轴压缩声发射试验,分析不同孔隙水压下砂岩的强度、变形及声发射信号特征.研究表明:在孔隙水压作用下,岩样的破坏形式大多为劈裂破坏.随着孔隙水压力的增加,砂岩的抗压强度和弹性模量明显降低,在达到应力峰值时的声发射信号峰值减小,应力峰值附近声发射信号突增明显.

In order to study the effects of pore pressure on the mechanical properties ot sand- stone, we use MTS 815.02 servo-controlled rock mechanical test system and PCI-2 AE system in acoustic emission tests of sandstone at triaxial compressive pressure under different pore pressures and analyzed the strength, deformation and acoustic emission characteristics. The results show that failure models of rock samples are mostly split failure under the effect of pore pressure. As pore pressure growing, the compressive strength and elastic modulus obviously decrease; the amplitude of acoustic emissions reduces corresponding to the peak stress, the acoustic emissions in the vicinity of the peak stress become intensive.