Abstract: Abstract: Gob-side entry retaining(GSER) by pumping concrete has been widely applied in coal mine in China. Due to limitations of many conditions such as underground space and working environment, Pipe blockage become an important restrictive factor in the process of GSER. This technical problem restricts the effective application and promotion of GSER. Based on field measurements and experience, Equipment manufacturing of pumping concrete, filling material preparation and operation mode have been optimized. As a result, prevention measures of pipe blockage was proposed and applied.

Key words: Key words: gob-side entry retaining, pipe blockage, cause analysis, prevention measure