水力耦合下节理砂岩三轴压缩渗透性能试验研究

Test Study on Triaxial Compressive Permeability Performance of Joint Sandstone Under Hydraulic Coupling

为了研究节理砂岩在高地应力、高水压耦合环境下性能发展情况,利用配有渗流装置的岩石三轴伺服试验机,开展不同围压与渗透水压下节理砂岩三轴压缩渗透性能试验。结果表明:节理砂岩三轴压缩渗透峰值强度随着围压增加而增大、随着渗透水压增加而减少,围压对峰值强度的积极影响要大于渗透水压对峰值强度的消极影响;初始渗透率受试件所处力学环境影响较大,围压和渗透水压变化均会引起初始渗透率改变,且其发展趋势与峰值强度相反;三轴压缩渗透初始阶段随着应力增加渗透率降低,弹性阶段渗透率则保持相对平稳状态,屈服阶段渗透率开始随着应力增加逐步上升最终达到最大。

In order to study the performance development of the joint sandstone under a high geostress and high hydraulic coupling environment,with an application of the rock triaxial servo test machine with a seepage device,the triaxial permeability performance test of the joint sandstone was conducted under the different confining pressure and seepage hydrogeological pressure.The results showed that the triaxial compressed permeability peak intensity of the joint sandstone would be increased with the confining pressure increased and would be decreased with the seepage water pressure increased.The positive effect of the confining pressure to the peak intensity would be higher than the negative effect of the seepage water pressure to the peak intensity.The initial permeability would be highly effected by the specimen in the mechanical environment,the aviation of the confining pressure and seepage wa-ter pressure both would cause the aviation of the initial permeability and the development tendency and the peak intensity would be contrary.At the initial stage,the triaxial compression penetration would be decreased with the stress increased permeability.At the elastic stage,the permeability would keep a relative stable state.At the yield stage,the permeability would be gradually increased with the stress increased and would reach the max value finally.