Application of the retained gob-side gateroad in a deep underground coalmine

Zhuji coalmine, a typical deep underground coalmine located in Huainan city, Anhui province of China, is characterised by rich gas, high in situ stress and low permeability. These geotechnical conditions cause serious problems including outburst, excessive gas emissions in the upper corner of the coal face, and low resource recovery resulting from large remaining coal pillars when using conventional mining methods. Retained gob-side gateroad (RGSG) is proposed to resolve these problems by eliminating the large coal pillars and extracting gas simultaneously. To achieve a scientific and reasonable application of the RGSG in the Zhuji coalmine, stress evolution in the surrounding rock of this roadway was studied using FLAC3D numerical simulation method. Then, a staged supporting strategy and corresponding parameters were proposed in terms of the characteristics of stress evolution. Finally, the effectiveness of the proposed method was discussed based on the field measurements and roadway maintenance was carried out for reuse during the adjacent panel excavation.