Force analysis and design of backfill retaining wall in large complex Goaf

The design of backfill retaining wall and construction technology are important factors that affect the cost, quality and safety of backfill. In order to reduce the cost, improve the quality and prevent the collapse of the Goaf, it calculates the total pressure and the maximum bending moment of the retaining wall with different filling height. Then it determines the filling height and the thickness of the retaining wall. Finally it studies the technical measures of dewatering, drainage and slurry running of backfill. The research shows that it should control the filling height within 1.5 m, the maximum thickness of backfill retaining wall should not be less than 3.8 m, it should connect the suspended dewatering pipe with the steel pipe embedded in the bottom of the retaining wall, and set up a drainage body to realize rapid dewatering and drainage, to reduce the pressure on the retaining wall.