Study On Supporting Structure And Parameters Of Full-Mechanized Caving Roadway Along Goaf In Dongfeng Coal Mine

Protecting roadway without coal pillar is an effective technical means to solve coal resource recovery and safe mining.The gob retaining roadway is the main form of protecting the roadway without coal pillar.It has experienced nearly 70 years development and the technology is maturing day by day.At present,it is popularized and applied in the whole country.Therefore,the use of gob retaining roadway along the gob has become an inevitable trend of coal mining.This paper takes the 3G01 working face of the 3#coal seam of the Dong Feng coal mine as the engineering background.Through the movement law of the overlying surrounding rock and the roof breaking law,the structure model of the surrounding rock and the mechanical model of the key block are set up,thus the calculation formula of the side support resistance of the roadway is obtained,and the mechanism of the filling body is analyzed from the rule of rock pressure in the overlying roadway along the goaf.Based on the basic requirements of the filling body,it has a certain early strength and rapid increase resistance characteristics,has a certain shrinkage and has a higher later strength,and provides a theoretical basis for the side support of the roadway along goaf.The filling material mainly analyzes the effect of the material on the performance of the filling material in the alley lane along the gob.Finally,the choice of cement is P · 042.5 cement.The plasticizer is selected as plasticizer A B(50%each,)the sand content is 60%.The final performance of the material can reach 8MPa in 1 day,the strength of 7 days is 28.5MPa,and the final strength is 45.5MPa in 28 days.According to the relation between backfill width and support resistance,the scheme of backfill support width is proposed as 1.0 mL 1.5mW 2.0mP2.5mP3.0m.The numerical simulation software FLAC3D was used to calculate the different width of backfill support.The displacement cloud map and horizontal stress of the surrounding rock of roadway were calculated respectively.When the width of the filling body is 2.0m,the roof can be maintained effectively and the maximum subsidence is 200 mm.Combined with Dongfeng Coal Mine,the effect of this scheme is monitored.The results show that the roof displacement and the displacement of deep surrounding rock are in the controllable range during the whole course of roadway retention,which shows that the supporting effect of the support scheme is obvious.The reasonable support width is verified when the width of backfill is 2.0 m.