Technology of Gob-Side Entry Retaining by Presplitting Blasting and Roof Cutting Pressure Relief

In view of the case that the conventional technology of gob-side entry retaining can't achieve the expected results, the test of gob-side entry retaining by presplitting blasting and roof cutting pressure relief in the transportation roadway of 1334 working face was implemented, and the reasonable blasting parameters and support parameters for roadway were designed. In the process of mining and retaining roadway, the accumulated deformation between roof and floor was 373mm, and two walls' was 63mm, which obtained better effect. By observing the internal state of hole, no separation phenomenon was found in the anchorage zone. It indicated that the technology of gob-side entry retaining by presplitting blasting and roof cutting pressure relief successfully reduced the difficulty of roadway maintenance, and effectively controlled the deformation of surrounding rock in roadway. Also, it reduced the excavating amount of roadway and relieved the pressure of mining and excavating replacement. Besides, the technology improved the recovery rate of coal resources, and was able to avoid the appearance of island working face.