基于磁场理论的矿岩加载损伤破坏表征研究

充填体与围岩的相互力学作用，除了接触带表壁附近可以通过贴置电阻应变片的方式进行应变值测量外，接触面及接触带附近的损伤破坏情况不易监测。基于此，应用磁场理论，将磁粉加入到配比试样中，充磁之后进行加载试验。通过特斯拉计测量试样表壁在加载过程中的磁感应强度变化，建立由表及里的损伤破坏联系规律。试验结果表明:加了磁粉的配比试样，在加载过程中各监测点处的磁感应强度值变化明显，特别是在内部裂纹扩展至临空面处的磁感应强度几乎减小至0.2 mT以下；而试样在加载过程中，各监测点的磁感应强度值随着压密破坏而变化；在未破坏时，不同区域有较一致的随试样内部压密相应磁感应强度增大的变化规律，而在试样加载破坏后，不同监测点磁感应强度变化起伏较大。

Study on damage and failure characterization of ore rock loading based on magnetic field theory

For the mutual mechanical action between the filling body and the surrounding rock, in addition to the strain measurement near the surface wall of contact zone through the method of laying the electric resistance strain gauge, the situation of damage and failure of the contact surface and in the vicinity of contact zone is difficult to monitor. The loading tests were conducted after magnetizing through adding magnetic powder into the allocated proportion samples by using the magnetic field theory. The change of magnetic induction intensity on the surface wall of samples during the loading process was measured by Tesla meter, and the relationship of damage and failure from surface to inside was established. The test results showed that the magnetic induction intensity at each monitoring point changed obviously during the loading process for the allocated proportion samples with magnetic powder, especially when the internal crack propagated to the free surface, the magnetic induction intensity reduced to below 0.2 mT. The magnetic induction intensity at each monitoring point changed with the compression failure. In the absence of failure, there was a more consistent change law that the magnetic induction intensity increases with the internal compression of samples in different area. While after loading failure of sample, the variation of magnetic induction intensity fluctuates at different monitoring points.