Research On Roof Falling Recognition And Early-warning In Fully-mechanized Face Based On Roof Pressure Data

With the development of the large-scale,specialized and intelligent equipment,the safe and efficient mining of mine was guaranteed,but roof fall may occasionally occur,resulting in discontinuous production and huge economic losses.The large-cutting height face in shendong minefield was studied as object.Analyzing ground pressure behaviours of support group in roof fall area and evolution process of severe roof fall,roof falling early-warning model with U-shaped zone as the main indicator was established and the stability control technology in roof falling hidden danger zone was proposed.(1)Status of Shield and Roof Intelli Sense system was improved.Roof falling model was was constructed and one-way cutting coal method and shield's advance were added.(2)Abnormal characteristics of support load in roof fall zone were found Severe roof falling goes through three stages including mining-induced influence,rib spalling and roof leakage,and roof deterioration.The ground pressure of the large-cutting height working face with super-long width is a shape of saddle.Ground pressure behavior characteristics in roof falling zone appears high-low-high similar to U-shape in inclined derection.Supports postures are instability on the strike.(3)Characteristics parameters were selected.Working cycle characteristic parameters were extracted.Setting pressure and safety value opening characteristics were evaluated.Based on the correlation theory,time-weighted average pressure and coal-cutting method as index for roof falling zone recoginiton are proposed.(4)Roof falling zone recognition and early-warning model were built.Pressure characteristics of all supports was analyzed to roof weighting according to the traditional pressure criterion.Based on image recognition technology,roof falling zone recognition model was constructed with time-weighted-average-pressure and cutting method.According to the evolution process of roof fall,roof fall early-warning model was established with U-shape range as main indicator.