Abstract: Considering such factors as mining pressure field, rock bearing capacity and support structure strength, the influence of span-height ratio for gob-side entry retaining on surrounding rock deformation was analyzed．Numerical simulation models were established for comparative analysis of nine schemes for gob-side entry retaining with different span-height ratio under large mining height, and the results showed that optimized section configuration can substantially improve the stability of and non-deformability of the surrounding rock structure. Plastic range and surrounding rock deformation both decrease with the reduction of roadway span when the roadway height has been determined．The surrounding rock deformation is more sensitive to the reduction of span when the roadway height exceeds 3 m, and the effect of optimization is more evident while the span-height ratio is less than 1.3．On this basis, the determination method and technology thoughts are proposed for optimal span-height ratio of gob-side entry retaining under large mining height, which has been successfully applied to the field test in 4.2 m large mining height face with the roadway height of 3.8 m and span-depth ratio at 0.79．

Key words: gob-side entry retaining, roadway support, surrounding rock deformation, span-depth ratio