Abstract: Aiming at the problem of large-section roadway support at the 4# intersection point of the -550 m horizontal bottom yard in Zhongjiu Iron Mine，the technical scheme for strengthening the support of the large-section roadway at the intersection was explored. First，the distribution of the plastic zone un⁃ der the gradual excavation of the 4# intersection and its nearby large-section roadway is analyzed by numeri⁃ cal simulation. According to the most unfavorable plastic zone range，the long anchor cable support design is carried out to ensure that the anchor cable has sufficient anchoring capacity. At the same time，the range of backfill grouting of the roadway wall is determined according to the range of the plastic zone to improve the anchoring effect of the bolt，and form the "long anchor cable-coupling grouting" joint strengthening support method. The joint reinforcement support method has been well applied in the large-section roadway at the 4# intersection，and the roadway deformation and slag drop have been significantly improved.

Key words: large-section roadway, anchor cable, grouting, strengthen support