渗透环境下受腐蚀裂隙岩石各区域密度变化特征

Density Variation of Different Areas of Fractured Rock Under Chemical Corrosion and Permeation

在外部荷载作用下,岩体不同区域物理力学性质有不同的响应。通过CT扫描实验,对渗透及无渗透环境下受化学腐蚀预制裂隙岩样在三轴压缩下不同区域密度变化特征进行了研究。结果表明:渗透环境下各区域CT数相对于初始扫描状态CT数的减小程度远大于无渗透环境,说明由于渗透水压力作用,加剧了岩石密度劣化程度。微裂隙压密阶段岩样的压密主要发生在裂尖所在层面,在裂尖所在层面处微裂隙压密又主要发生在岩样中心区域,无渗透环境下该现象比渗透环境突出得多。在无渗透环境下,上、下裂尖所在扫描层CT数变化率远大于其它各扫描层;而渗透环境下上、下裂尖所在扫描层变化规律则与其它各扫描层相似,表明渗透水压力对各区域均产生明显的破坏影响作用。

The physical and mechanical properties of different areas of rockmass are different under external loading,so it is important to study the density variation of different areas of fractured rock.Real-time computerized tomography(CT)experimental results on different areas of fractured rock during triaxial compression with chemical corrosion and permeation are presented.The test results showed that the change rates of CT number of each area reduce greater under permeation environment than that under no permeation,which indicates that the density becomes smaller because of permeation and water pressure.The compaction occurres mainly in the level of crack tip and its center area in this stage of microfissure compaction.The change rates of CT number in the level of crack tip are much greater than other scanning slice under no permeation,but it is similar for all scanning slice under permeation which shows that the permeation and water pressure have obvious effect of destruction to all areas.