层状砂岩静动力学特性对比

Comparison of Static and Dynamic Characteristics of Layered Sandstone

为研究层状砂岩在冲击荷载和静荷载作用下层状砂岩的力学特性,对层理倾角为0°、15°、30°、45°、60°、75°、90°的试样进行冲击压缩实验和静力压缩实验。对2种试验的结果进行对比分析发现:随层面倾角增大,砂岩峰值强度先减小再后增大;试样冲击压缩时试样峰值强度较大;静载条件下,随砂岩倾角的增大,弹性模量与强度均而先增加后减小再增加,冲击压缩时,随角度的增加,弹性模量的变化呈先增加再减小的趋势,强度的变化呈先减小后增大的“U”形;单轴压缩实验中,倾角为0°~75°试样发生剪切破坏,倾角为90°的试样发生劈裂和剪切混合破坏;冲击荷载作用下,试样在倾角为0°~60°时破碎形状为块状,在倾角为75°和90°时破坏形状为块状和片状混合。

In order to study the mechanical properties of layered sandstone under impact load and static load,impact compression test and static compression test were carried out for samples with bedding dip angles of 0°,15°,30°,45°,60°,75°and 90°.Comparing and analyzing the results of the two tests,it is found that as the bedding angle increases,the peak strength of the sandstone first decreases and then increases.The peak strength of the sample is greater when the sample is under impact compression.Under static load conditions,with the increase of the angle,elastic modulus and strength both increase first,then decrease and then increase.During impact compression,with the increase of angle,the change of elastic modulus first increases and then decreases.The change of strength shows an U-shaped trend,which decreases at first and then increases.In the uniaxial compression experiment,the sample with an inclination angle of 0°~75°undergoes shear failure,and the sample with an inclination angle of 90°undergoes cleavage and shear mixed failure.Under the impact load,the fracture shape of the specimen is blocky when the dip angle is 0°~60°,and the failure shape is a mixture of block and sheet when the dip angle is 75°and 90°.