EXPERIMENTAL RESEARCH ON FAULT MOVEMENT AND VARIATION LAWS OF MAGNETIC INDUCTION SIMULATED BY MAGNETOSPHERE ROCK PLATES

With the maximization of the project scale, many tunnels may be affected by the active fault zone. How to accurately predict and describe the situation of the fault has become a critical problem in such projects. In traditional mechanical method, only using the stress and strain cannot accurately describe the internal cracking of strata. A large number of tests have showed that the sound, the light and the magnetic signals occur in the rock failure. Based on the changing-priority and measurement non-contact, the variation laws of the magnetic induction were researched in this study. The magnetosphere was implanted into the rock plate specimen and some springs were applied to simulate the lateral load. Through cyclic loading test, the variation laws of the magnetic induction, the vertical force, and the crack width were obtained. The test result showed that the magnetic induction was proportional to the vertical force and crack width. In loading phase, the cracks opened and the magnetic induction increased; in unloading phase, the cracks closed and the magnetic induction decreased. Both in loading and unloading phase, locking phenomenon occurred and the fault destroyed in classification model. The vertical force varied in wavy-shaped curve, corresponding with it, the crack width and magnetic induction varied in Ladder-shaped curve.