Distributed Sensing And Analysis For Deformation Of Surrounding Rock In Roadway Under Mining

In the process of coal mining in our country,the law of deformation and failure of surrounding rock is a traditional and basic topic of research during the process of mining.In the process of mining,accurately understand the distribution and variation characteristics of stress field and deformation field of surrounding rock to ensure safe and efficient of coal mining and solve the outstanding problems faced in deep mining etc.,it has the vital significance.In this paper,using the method of the combination of field measurement with FLAC3i numerical simulation,we carry out in-depth research for the deformation and failure law of surrounding rock of 1231（1）working face on the Pan Yidong mine during mining.By introducing BOTDR（Brillouin Optical Time Domain Reflectometer,Brillouin Optical Time Domain Reflectometer）,which is a distributed Optical fiber sensing technology,and applied it to distributed sensing for the deformation of surrounding rock under the influence of mining,thus successfully collected the original strain of the surrounding rock during the process of mining,and then made a deep analysis of the measured strain data,finally established a three-dimensional geological model of stope space by FLAC^3D software.The achieved results are as follows:（1）Mining deformation of surrounding rock distributed monitoring method based on BOTDR technologies was proposed.（2）According to strain distribution of the sensing optical fiber and the change of situation,analysis of distribution characteristics of abutment pressure for the stope space:working face,the influence scope of lead abutment pressure is 115-120m,the obviously influence scope is about 70-90m and the dramatic influence scope is about 25-35m,the stress peak away from coal wall is 4-12 m.（3）Set up FLAC^3D numerical model Based on 1231（1）working face of Pan Yidong mine,and according to the the consistency check of calculation and the correlation coefficient and the maximum relative error of the measured deformation distribution,the model parameters are optimized and calculated characteristics,plastic zone,displacement of roof and floor strata change rule and the influence of abutment pressure of stress distribution of the stope space.The results of numerical simulation are basically identical with the measured results.In a word,using BOTDR which is distributed optical fiber sensing technology can get deformation and destruction features of of the stope space,through the combined with numerical simulation,can acquire deformation field and stress field of the spatial distribution and change rule of stope in the process of mining.The study provides a new method for detection and analysis for mining under the influence of the deformation of roadway surrounding rock.