层理倾角对岩石力学与声发射特征的影响研究

层理倾角对岩石受载下的力学性质和声发射特征有重要的影响。通过对0°、15°、30°、45°、60°、75°、90°倾角试样的单轴压缩模拟试验,获得了层理岩石抗压强度、破坏模式、声发射振铃数等随层理倾角的变化规律。研究结果表明:1随着层理倾角的增加,试样单轴抗压强度存在着先增大后减小又增大的过程;2大致分为3种破坏模式,15°和30°倾角试样劈裂与剪切破坏并存,以劈裂破坏为主,属于先基质后层理型破坏;45°、60°、75°倾角试样劈裂裂纹相对较少,剪切破坏显著,属于先层理后基质型破坏;0°和90°倾角试样出现大断口,属于局部强烈基质型破坏;30°、15°、30°和90°倾角试样声发射静默期长,活跃期短,其最大声发射数大,声发射增长速率快;而45°、60°和75°倾角试样静默期短,活跃期长,其最大声发射数小,声发射增长速率慢。

Effect of Bedding Angle on Mechanical and Acoustic Emission Characteristics of Layered Rock

Bedding angle has an important influence on the mechanical properties and acoustic emission characteristics of rock. By uniaxial compression simulation on layered rock with 0°,15°,30°,45°,60°,75°,90° inclination,the variation of com-pressive strength,failure mode,acoustic emission number with bedding dip were obtained,and the results showed that:① with the increase of bedding angle,uniaxial compressive strength of the sample first decreases and then increases;②There are three kinds of failure modes. Splitting and shear failure coexist in 15° and 30° samples,and splitting failure is the main part,which is the failure mode of from matrix to bedding;shear failure plays significant part in 45°,60°,75° samples,with failure mode of from bedding to matrix;big fracture areas exists in 0° and 90°specimens,belonging to a local strong matrix-type failure;③ for 0°,15°,30° and 90° samples,silent period of acoustic emission is long and its active period is short,and the maximum number is large,and acoustic emission increases fast;the 45°,60° and 75° samples exhibit the opposite behavior correspondingly.