含软弱夹层岩石材料的损伤破坏过程

对含软弱夹层的岩石材料损伤破坏过程进行了试验观测和计算模拟研究。试验所用岩石材料为房山大理岩，平板状试件中心预制的割缝用较大理岩软弱的水泥砂浆充填。对试件受单轴压缩过程中，岩石材料和充填水泥沙浆中微裂纹的萌生、扩展、连通和闭合等过程进行了观测分析及显微照像。用NOLM程序中的低抗拉应变软化本构模型对试验结果进行了有限元模拟计算。计算中，试件的几何形状与试验所用的完全相同，岩石材料的强度取为填充材料的5倍，加载采用试件的一端固定另一端逐步增加位移的办法来实现，由位移值反算出对应的远场单轴压缩载荷，将计算结果与试验观测结果进行对比，吻合较好。与野外观测相比，填充割缝能够更好地模拟实际的地质构造现象。

RESEARCH ON FRACTURING AROUND CEMENTED SLOT IN ROCK SPECIMEN

The finite element simulation of sub-crack development around a fracture cemented with grout inFangshan marble plate specimen under uniaxial compression is carried out. The initiation,coalescence andrecovery of sub-crack around as well as inside the cemented fracture are photographed and analyzed underreal-time scanning electron microscope observation. Finite element computation of the crack process using NOLMprogram with a strain-softening constitutive model of low tensile strength is performed. The computation resultrepresents the experimental observation fairly well. The real fracture or fault system in earth,no matter in small orlarge scale,has filling materials such as fault gouge or fault clay which has lower strength. Compared with thefield observation,the cemented one should be a better simulation of the actual geological situation. Therefore theresults give a more comprehensive understanding and simulating of fracturing process in geologic structure.