The occurrence and nature of shaft rockburst in the Yinxin gold mine are recorded and analyzed. Rockburst happens along an obvious south-north orientation. The ground and surrounding rock stresses are measured in this...The occurrence and nature of shaft rockburst in the Yinxin gold mine are recorded and analyzed. Rockburst happens along an obvious south-north orientation. The ground and surrounding rock stresses are measured in this mine. The research indicates that the directivity of rockburst is closely related to geological structure and to abnormal distri-bution of ground stress in some parts of the mining area. The mechanism of past rockbursts is discussed based upon the theory of fracture mechanics. Some rockburst release measures and their execution in the Yinxin Gold Mine are de-scribed. These measures have been successful in eliminating rockburst.展开更多
We studied the dynamic fracture mechanical behavior of rock under different impact rates. The fracture experiment was a three-point bending beam subjected to different impact loads monitored using the reflected causti...We studied the dynamic fracture mechanical behavior of rock under different impact rates. The fracture experiment was a three-point bending beam subjected to different impact loads monitored using the reflected caustics method. The mechanical parameters for fracture of the three-poim bending beam specimen under impact load are analyzed. The mechanism of crack propagation is discussed. Experimental results show that the dynamic stress intensity factor increases before crack initiation. When the dynamic stress intensity factor reaches its maximum value the crack starts to develop. After crack initiation the dynamic stress intensity factor decreases rapidly and oscillates. As the impact rate increases the cracks initiate earlier, the maximum value of crack growth velocity becomes smaller and the values of dynamic stress intensity factor also vary less during crack propagation. The results provide a theoretical basis for the study of rock dynamic fracture.展开更多
文摘The occurrence and nature of shaft rockburst in the Yinxin gold mine are recorded and analyzed. Rockburst happens along an obvious south-north orientation. The ground and surrounding rock stresses are measured in this mine. The research indicates that the directivity of rockburst is closely related to geological structure and to abnormal distri-bution of ground stress in some parts of the mining area. The mechanism of past rockbursts is discussed based upon the theory of fracture mechanics. Some rockburst release measures and their execution in the Yinxin Gold Mine are de-scribed. These measures have been successful in eliminating rockburst.
基金the support of the National Natural Science Foundation of China (Grant No.50774086 and 50874109)
文摘We studied the dynamic fracture mechanical behavior of rock under different impact rates. The fracture experiment was a three-point bending beam subjected to different impact loads monitored using the reflected caustics method. The mechanical parameters for fracture of the three-poim bending beam specimen under impact load are analyzed. The mechanism of crack propagation is discussed. Experimental results show that the dynamic stress intensity factor increases before crack initiation. When the dynamic stress intensity factor reaches its maximum value the crack starts to develop. After crack initiation the dynamic stress intensity factor decreases rapidly and oscillates. As the impact rate increases the cracks initiate earlier, the maximum value of crack growth velocity becomes smaller and the values of dynamic stress intensity factor also vary less during crack propagation. The results provide a theoretical basis for the study of rock dynamic fracture.
