Study On Surrounding Rock Control Of Gob-side Entry Filling In Lingzhida Hard Top Plate Working Face

In view of the difficult problems such as the adoption of large coal pillar to protect the roadway,the serious loss of coal resources,the difficulty of roadway maintenance in the adjacent working face and the difficulty of hard top plate caving in the remaining roadway,the control technology of cutting off the hard top plate to fill the surrounding rock of the remaining roadway along the go after is put forward.That is to say,through the prefer splitting blasting of the side roof of the go after to weaken the roof,under the action of mining stress,the hard roof will be transformed into a direct roof caving,cutting the backward and broken swelling slag to play a supporting role in the upper strata,limiting its rotational deformation,reducing the fracture impact load of the hard roof,and manually transferring the fracture line of the roof to the side of the go after,the roof forms the short arm beam structure of the roof in the side It reduces the length of the lateral cantilever,reduces the additional load on the side support of the roadway,thus improves the stability of the retained roadway and reduces the difficulty of the surrounding rock control of the retained roadway.In this paper,firstly,the failure characteristics of the surrounding rock of the retained roadway under the condition of hard roof cutting or not are analyzed,the pressure relief mechanism of the roof prefer splitting and cutting at the go after side is studied,the mechanical model of the surrounding rock stability of the "surrounding rock structure roadway side support body" under the condition of cutting the roof is established,and the calculation formula of the resistance of the side support of the roadway is deduced;then,the influencing factors and laws of the stability of the surrounding rock of the retained roadway under the condition of cutting the roof are studied,and the results are obtained Based on the analysis of the stability mechanism of the surrounding rock of the side entry filling and retaining in the thick coal seam face,the deformation law of the surrounding rock of the side entry retaining with different side entry support resistances is analyzed,and the reasonable side entry support mechanical properties are obtained.According to the material mechanical properties and the production geological conditions of the retaining,the reasonable side entry support parameters and construction technology are designed.Finally,the concentrated energy prefer splitting blasting is proposed The comprehensive surrounding rock control technology of breaking the gob side roof,filling by the side of the roadway and strengthening the support by the single hydraulic prop in the roadway is applied to the 15209 working face of Ling Zhi Da coal mine.Thesurrounding rock control effect is evaluated by the deformation of the surrounding rock in the remained roadway,the support load of anchor bolt(cable),the stress and deformation of the filling body.The field application shows that the above support technology can effectively control the high and hard mining The strong deformation of the surrounding rock in the gob side entry of the roof,the stability of the surrounding rock and the filling body,and the good control effect of the surrounding rock have been achieved.