Experimental Study on Deformation Characteristics Monitoring of Overlying Strata Based on Distributed Optical Fiber

Abstract

The deformation, failure mode and internal stress evolution law of overlying strata during coal mining are important issues in the field of mining engineering. It is vital that the deformation and pressure law of overlying strata in the mining process of the working face are monitored in real time by scientific and effective monitoring means. In this paper, distributed optical fibers are horizontally and vertically embedded in the model to monitor the deformation characteristics and stress-strain state of the overlying strata. The results show that the “saddle-shaped” frequency shift curve of horizontal sensing optical fiber reflects the dynamic change process of the overlying strata breakage during the 1-2 coal mining process; the initial pressure and period pressure on the overlying strata of working face can be distinguished by using the variation of Brillouin frequency shift, and the strain distribution characteristics of similar model throughout the mining process were revealed by the space-time evolution regularities of distributed optical fiber.

Keywords

• overlying strata deformation
• distributed optical fiber sensing technology
• similar model
• space-time evolution regularities
• stress-strain