Research on the key technology of distributed fiber monitoring in tunnel bottom drum

The bottom drum of the roadway is one of the common dynamic pressure phenomena in the process of coal mine production, which can easily affect the material transportation and personnel walking of the coal mine, even destroy the roadway when it is serious, which restricts the safety and efficiency of coal mine production. To improve the backward monitoring method of the tunnel bottom drum deformation, a method of monitoring the bottom drum of the roadway based on distributed fiber monitoring technology is proposed. Through theoretical analysis, the relationship between the distributed fiber deformation and the tunnel bottom drum is proposed. To verify the accuracy of the formula, a similar model is built. Distributed optical fiber is arranged in the model, and the speckle measurement points are arranged on the surface of the model. The method of DIC distributed fiber monitoring is used to verify. The monitoring results show that the formula proposed in this paper can effectively monitor the displacement change of rock strata. At the same time, the coupling between optical fiber and rock determines the accuracy of the measurement results. The better the coupling between optical fiber and rock, the more accurate the measurement results are.