红层泥岩力学参数与声速相关性试验研究

Experimental Study on the Correlation between Mechanical Parameters of Red Mudstone and Acoustic Velocity

声波在岩石中的传播速度与岩石强度、变形特性密切相关.以重庆红层地区的169个泥岩样品为研究对象,运用单轴抗压强度试验、单轴压缩变形试验及声速测试等方法进行对比试验研究,采用不同函数关系建立了红层泥岩单轴抗压强度R、弹性模量Ee与纵波声速Vp的关系,比较分析：认为红层泥岩采用二阶多项式表达它们的关系最佳,红层泥岩单轴抗压强度R与纵波声速Vp经验关系为：R =4.7 ×10^-6×Vp^2-0.023 4Vp ＋33.771;Ee与纵波声速Vp经验关系为：Ee =0.003 7×Vp^2-19.312Vp^2 ＋27 333.结合某工程地勘钻孔声波测试成果,运用建立的相关关系对岩体力学参数进行了计算分析,提出了该场地的单轴抗压强度建议值为5～6 MPa,岩体弹性模量建议值为2 000 ～3 000 MPa.

The velocity of acoustic wave propagation is closely related with rock mass strength and deformation characteristics.Uniaxial compressive strength tests,uniaxial compression tests and sound velocity test were conducted on 169 red mudstone samples from the red-layer region in Chongqing.Relationships between uniaxial compressive strength R,elastic modulus Ee and wave velocity Vp are established by different functional relationships.Comparative analysis results show that their relationship expressed using second-order polynomial is the best.The empirical relationship between R and Vp could be expressed by R =4.7 × 10^-6 × V2^p-0.023 4 Vp ＋ 33.771,and the relationship between Ee and Vp is Eo =0.003 7 × V2^p-19.312V2^p ＋27 333.The rock mechanics parameters of an engineering example were calculated and analyzed by using the established relationships.It was found that the recommended value of uniaxial compressive strength of the example is 5-6 MPa,and the elastic modulus is 2 000-3 000 MPa.