Relationship between the strength formation rate of the filling bodyand the advancing speed of the working face

Abstract

In view of the geological production characteristics of high concentration cemented backfilling(HCCB) in goaf of Xinyang coal mine,and according to the relationship between the strength of cemented filling materials and condensation time,the area of the filling body is divided into two regions in the direction of advance:the intensity growth region and the intensity constant region.Based on the analysis of strength boundary of the two regions,the mechanical model of roof beam supported by "coal wall-support-filling body" is established.By analyzing the stress of the roof rock beam,the shear forces and bending moments of the roof rock beam were established. Bearing reaction forces and the bending moments for two solid support end of rock beam were figured out.According to the concept of the filling mining limit span and the time relation with HCCB strength formation,the quantity relationship between the advancing velocity of the working face and the strength formation rate of the filling body was calculated.The results show that:The maximum shear force and maximum bending moment of rock beam are located at the intersection of rock beam and coal wall:The working resistance of the working face support and the supporting ability of the filling body have a great effect on the distribution of the shear forces and bending moments of the roof rock beam;the reasonable advancing speed of Xinyang Mine working face No.10203 is 3.2 m/d,and 4 shear cuts per day.

Keywords

• coal mine
• cemented filling mining
• filling-body strength
• mechanical model
• advancing speed of working face