Reasonable Parameters of Combined Filling Body in Gob-side Entry Retaining Under Roof Cutting Condition
Aiming at the problems of unclear bearing characteristics and blind parameter selection of combined filling body under the condition of hard roof cutting,taking 90203 return airway of a coal mine as the research object,theoretical analysis,numerical simulation and field test were used to study the stress characteristics of combined filling body and the deformation law of surrounding rock of roadway under the conditions of different width of filling body and different height of upper and lower layers of filling body after roof cutting.The superimposed laminate model was established,the stress state and deformation of the filling body under the condition of roof cutting were analyzed,and the calculation formula of the reasonable parameters of the combined filling body after roof cutting was given.The results show that with the increase of the height of the upper layer of the combined filling body,the overall bearing capacity of the filling body undergoes a phased change,and the stress it bears increases first and then decreases.With the increase of the width of the filling body,the adaptability of the filling body to the surrounding rock changes,so that the stress it bears shows a non-linear decreasing trend.The practice shows that during the mining of 90203 working face,the combined filling body of gob-side entry retaining is stable,and the maximum displacement of the roof and floor of the return airway and the two sides was 307 mm and 319 mm,respectively,which are within the controllable range.
Roof cutting and pressure reliefCombined filling bodyGob-side entry retainingRoadway control
万方数据
维普
