岩石直接拉伸与压缩变形的试验研究

采用自行研制的可对同一岩石试样进行单轴压缩和直接拉伸的试验装置,对3种岩石进行了压缩和直接拉伸试验.结果表明,这3种岩石的压缩弹性模量均大于拉伸弹性模量,压缩与拉伸弹性模量之比分别为1.1,1.4,2.5.压缩泊松比也大于拉伸泊松比.研究表明:直接拉伸下切线泊松比随荷载的增加而减小,与压缩下泊松比的变化相反.

Experimental research on deformation of rocks in direct tension and compression

Laboratory tests of direct tension and compression were conducted for three rock types with a testing unit that can perform both compression and direct tension on a same rock sample. The results showed that for most rock samples, the obtained Young’s moduli in compression EC were greater than those in tension ET. For Gaofeng limestone, the EC/ET ratio was 1.1; for Gaofeng pyrite, the ratio was 1.4; and for Songshujiao marble, the ratio was 2.5. The average values of Poisson’s ratios in compression were also greater than the values in tension. It was also found that the tangent Poisson’s ratios in tension decreased with the increasing applied loading, which was opposite to the behavior in compression.