基于应变局部化的双裂纹岩石岩桥贯通及试件失效模式试验研究

he crack in the rock will initiate, propagate and coalesce under loading. The procedure has a clear effect on rock's mechanical property and damage property. Based on the uniaxial compression experiment on the rock with two precast flaws, the strain field of the whole rock and the strain filed of rock bridge area during the loading procedure are obtained. It has been found that the sample clearly appears local strain until breaking during loading. The high local strain area which is formed in prime of loading dominates the range and trend of strain field during loading. There are three modes of rock bridge fracture of two flaws' rock: inner tips' fracture, outer tips' fracture, and both. The degree and distribution of rock bridge have an effect on the formation of local strain area, crack initiation, propagation, coalescence and the mode of failure from macroscopic view. The mode of rock bridge fracture has an important effect on the strength characteristics.