中文摘要：

通过调查某磷矿的岩爆现场,并利用扫描电镜对磷块岩的岩爆碎屑进行细观分析,研究了岩爆的细观演化。研究结果表明：1）磷块岩岩爆碎屑的细观结构均较致密,岩爆碎屑板面主要呈张拉破坏特性,岩爆碎屑边缘断口主要呈张剪破坏特性;2）岩爆碎屑板面因受相邻岩体板面的相互挤压作用而呈断口表面的微小塑性变形特性,在碎屑边缘断口的交叉面附近因受应力集中作用而产生部分塑性变形;3）当岩体中存在优势裂纹时,岩体受优势裂纹作用产生沿晶断裂张剪破坏;当岩体中无优势裂纹时,岩体主要受压剪作用下的穿晶破坏;4）可将磷块岩的岩爆细观演化过程划分为岩体沿切向方向上的张拉破坏阶段、优势裂纹引发沿晶断裂致张剪破坏阶段或无优势裂纹时板面间的挤压引起塑性变形阶段、岩体应力集中产生塑性变形致使裂纹源的产生与贯通失稳阶段。

英文摘要：

The rock burst evolution were studied by investiga ring the rock burst site in a phosphate mine and micromechanies analysis of the phosphate rock burst fragments using the scanning electron microscopy （SEM）. The results indicated that： 1） The microstructures of rock burst fragments show dense structure. And rock burst fragments on board surface is characterized by tensile failure, while its edge point is characterized by shear fail ure. 2） The micro-plastic deformation is characteristic on the board surface of rock burst fragment due to the mutual compres- sion near the rock. And the plastic deformation near the edge of rock burst fragment is caused by stress concentration. 3） When there are dominant cracks in the rock mass, the phosphate rock mass mainly affected by dominant crack shows the extrude shear fracture along the crystal damage. But it shows the press shear fracture by crystal damage, when there are no dominant cracks. 4）The rock burst micro-evolution of phosphate can be divided into three stages： the tensile failure stage of phosphate along the tan- gential stress, the extrude shear fracture stage with dominant cracks and the press shear fracture without dominant cracks, and the stage of crack source formation and connection destabilization failure caused by plastic deformation resulting from stress concen- tration.