论文部分内容阅读
Overburden stratum deformation monitoring is one of the key problems in mining ground control.Using geophysical method through surface drilling to detect stratum movement is commonly used in the industry.In this paper,a measurement method for overburden deformation detecting based on the distributed optical fiber sensing(DOFS)technology was conducted,a DOFS-based stratum deformation monitoring experiment was performed with three physical model tests in the laboratory,and the optical fibers were installed vertically in the models to simulate the field testing.The results suggest that the DOFS method precisely detects the rock mass deformation and stratum structure forming with the Brillouin frequency shifts(BFS)characterization.Firstly,the basic law of BFS distribution is summarized,the BFS distribution will present a continuous change,a stage form change and a recovery change,which are the symbol of rock mass fracture and broken in the overburden deformation.Secondly,the overburden deformation and structural evolution can be characterized by two main l3FS distribution forms.One is the three-phase form,which reflects the characterization of the horizontal three zone.The other one is the three-stage form,which are corresponding to the vertical three zones.Then,a concept of BFS average degree is proposed to describe the overburden roof weighting,and the calculation results are match to this experiment observation.Based on those analysis,a characterization model is established to illustrate the inversion mechanism of BFS distribution that reacts to the overburden deformation,the macroscopic and qualitative expression of overburden deformation based on DOFS measurement is expounded.In the end,the feasibility and reliability of this DOFS-based investigation method are proved by the measurement comparison validation.This study constructs a solid theoretical and methodological foundation for the practical application of DOFS measurement technology in the mining ground control research.