中文摘要：

岩样为大理岩,进行了围压20MPa、不同轴压的常规三轴压缩试验和核磁共振测试试验,测得大理岩在三轴压缩后的应力-应变曲线、弛豫时间T2谱分布和孔隙度,建立了孔隙度与损伤度之间的函数关系。结果表明,（1）孔隙度和轴压比的拟合函数显示,随着轴压的增加,大理岩孔隙度呈指数增长;轴压比小于70%时,大理岩产生弹性变形,孔隙度增长较小,轴压比处于70%~90%阶段时,大理岩以塑性变形为主,孔隙度明显增大,轴压比大于90%时,大理岩产生强烈扩容,孔隙度成倍增长;（2）大理岩内部裂隙数量和裂纹开度均随着轴压的增大而不断增大;（3）损伤度与孔隙度或轴压比的函数关系表明,随着轴压比的增大,大理岩的损伤度不断增大,相同外荷载产生的有效应力也不断增大。

英文摘要：

Taking the marble as the specimens, conventional triaxial compression tests under 20 MPa confining pressure and different axial compressions are first conducted. Then the nuclear magnetic resonance （NMR） tests are conducted on the loaded specimens. The stress-strain curves, crosswise relaxation time T2 distribution and rock porosity are obtained. The function about damage degree and porosity is established. The results show that： （1） The fitted function about porosity and axial compression ratio indicates that porosity of marble increases exponentially with the increase of axial compression. When the axial compression ratio is below 70%, specimens perform elastic deformation and the increase of porosity is small. When the axial compression ratio is above 70% and below 90%, the specimens perform plastic deformation and the porosity of specimens increases significantly. When the axial compression ratio is above 90%, the dilatancy of specimens increases sharply and the porosity of specimens multiplies. （2） The number and size of microcracks in specimens increase with the increase of axial compression. （3） The function about damage degree and axial compression ratio indicates that as the axial compression ratio increases, the damage degree of marble grows, and the effective stress of external loads also grows.