含不同倾角天然软弱夹层的大理岩破坏试验

Experimental test on marble containing natural weak interlayer of different angles

为研究不同倾角的天然软弱夹层对大理岩的影响规律,分别基于0°,30°,45°,60°和90°的天然软弱夹层岩样进行单、三轴压缩试验.试验结果表明夹层对岩石的强度具有“弱化效应”：1）单轴压缩时,夹层岩样整体上表现为劈裂型破坏,但在倾斜夹层处会出现不同程度剪切滑移,产生拉剪复合型破坏.三轴压缩时,夹层岩样发生剪切破坏,其中60°夹层岩样的破裂面与夹层面完全重合.2）不同倾角的夹层对岩石的弱化作用不同,整体趋势为岩石的强度随夹层倾角的增加呈现出先减小、再增大的特点,当夹层角度为60°时,夹层对岩样的弱化效应最为显著.3）大理岩三轴压缩时沿夹层破坏的夹层倾角范围为51°～69°,理论与试验结果吻合较好。

To study the influence of natural weak interlayer of different angles on marble,uniaxial and triaxial compression tests were carried out on marble specimens containing interlayer of 0°,30°,45°,60°and 90°angles.Experiment shows that interlayer has ＂ weakening effect＂ on the strength of marble.The results show that：1）The specimens of marble with interlayer failed with splitting mode,but along the inclined interlayer different levels of shear slippage appeared,which lead to the ultimate uniaxial failure as tensile-shear recombination mode.Under triaxial compression the interlayer specimens will be failed with shear mode and the failure surface was the same as the interlayer plane in 60°interlayer specimen.2）Different angles of interlayer have different weakening effects on the rock.The changing trend of strength of the different specimens with the increase of the interlayer angle were decrease and then increase.The weakening of the interlayer for the rock are most significant when interlayer angle is 60°.3）When marble specimens were failed along the interlayer plane under triaxial compression,the interlayer angle was between 51°and 69°,and the theoretical results agreed well with the test results.