Application of Connected Long Bolt Support in High Cutting and Narrow Coal Pillar Gateway of Deep Mine

In order to solve a deep broken depth of the sidewall along the gateway with high cutting narrow coal pillar in deep mine and a low extension rate of ana nchor, a connected long bolt applied to the roof support of the gateway was provided to replace the anchor and a rigid long thread bar connected bolt applied to the gat eway sidewall was provided to replace the short bolt support technology.Based on the site measurement and the FLAC3 Dnumerical simulation, a connected long bolt s upport plan was set up, the bolt support parameters were optimized and a site comparison experiment was conducted.The results showed that there was a high relation ship between the anchor support effect and roof subsidence value.Due to the high support strength of the anchor, when the roof subsidence value was not over the exte nsion value of the anchor, many anchors were broken and failure occurred and the connected long bolt with no broken phenomenon occurred had good support functio n.The rigid long thread bar connected bolt support would well contral the convergence value between the two sidewalls during the mining and excavation period and co uld reduce the deformation and stability time of the two sidewalls.