论文部分内容阅读
基于对赵固一矿二1煤层顶板中砂岩的超声波测试、常规单轴以及三轴压缩试验,研究顶板中砂岩纵波速度、强度和平均模量之间的关系,以及围压对试样强度和变形的影响关系.试验结果表明:由于中砂岩受成岩环境的不同,造成岩样内部的材料结构存在差异,同一钻孔取得的岩芯自上而下颗粒由细变粗;岩样纵波速度、平均模量和强度依次增大,但平均模量、纵波速度和强度都是试样的综合宏观表现,三者没有明确的力学关系;三轴压缩强度、平均模量与围压具有相关性,多个试样经不同围压试验结果联合回归得到的结果能够表征中砂岩的强度特征;试样的差异主要体现在砂岩内部尺度较小的裂隙、层理面的数量和方向,其数量和分布的不同必将引起试样的波速、平均模量和强度的差异.
Based on the ultrasonic tests and the conventional uniaxial and triaxial compression tests on the sandstone in the roof of No.21 Coal Seam of Zhaogou Coal Mine, the relationship between the longitudinal wave velocity, strength and average modulus of sandstone in the roof was studied and the effect of confining pressure on the strength and The results show that due to the difference of diagenetic environment in the middle sandstone, the material structure inside the rock sample is different, and the top-down grain size of the core core obtained by the same drilling hole is reduced from coarse to coarse. The longitudinal wave velocity, The average modulus and strength increase in turn, but the average modulus, longitudinal wave velocity and strength are the overall macro-performance of the sample, the three have no clear mechanical relationship; triaxial compression strength, the average modulus and confining pressure are related, The results of multiple regression tests with different confining pressure test results can characterize the strength characteristics of medium sandstone. The differences of the samples are mainly reflected in the small scale cracks and the number and orientation of bedding plane in the sandstone. The number and distribution The difference will inevitably cause the sample wave velocity, the difference between the average modulus and intensity.