Compression-consolidation-creep-diagenesis process of compacted gangue and its equivalent mining height model analysis

XU Lei; WANG Siyu; ELMO Davide; DING Shuxue; LIU Honglin; LI Wenfeng; HONG Zijie

doi:10.16186/j.cnki.1673-9787.2023060045

Abstract：Objectives To investigate the compression-consolidation-creep-diagenesis process of compacted gangue and its equivalent mining height model,using the 1102 gangue filling face of Tingnan Coal Mine as the engineering background,Methods the study employed theoretical analysis,numerical simulation,labo-ratory tests,and field measurements.Results The study found that the maximum roof control gap for the gangue filling face was calculated as the cutting depth plus the end face distance,top beam length,and contact distance of the rear support to the gangue.The rotation and subsidence amount of the roof equalled the maximum roof control gap multiplied by the sine of the support's tilt angle(ht=Lmax×sinθ).The back-fill space height behind the frame equalled the mining height minus the roof's rotation and subsidence amount,underconnecting amount,and bottom heave behind the frame.The compression-consolidation-creep-diagenesis process of compacted gangue in the fill space and their corresponding compression rates were:skeleton adjustment segment(7.42%),slow compression segment(5.39%),consolidation settle-ment segment(0.34%),and creep-diagenesis segment(12.38%).The total rechargeable compression rate was 25.53%.Based on the equivalent mining height,the four-stage equivalent mining height of the 1102 face was:skeleton adjustment segment(0.94 m),slow compression segment(1.10 m),consolidation settlement segment(1.11 m),and creep-diagenesis segment(1.48 m).Conclusions Through the compari-son of probability integration method prediction,numerical simulation,and subsidence observation,it was observed that the surface subsidence curves of the main section of the 1102 working face in strike and incli-nation were bowl-shaped.The surface subsidence curve was gentle in the first two stages and steep in the last two stages.