Coal roadway rapid driving technology and equipment with integrated drilling and anchoring and its application

This paper analyzes the current situation and existing problems of coal roadway driving technologies and equipment, introduces the new mode, technology, equipment of coal roadway rapid driving with integrated drilling and anchoring and its underground applications. The bolting technologies and equipment with integrated drilling and anchoring are developed which include the integrated drilling and anchoring bolt, pumpable resin, drilling boom and drill rig as well as bolts cartridge with integrated drilling and anchoring, pump unit and intelligence control system. The new technology simplifies the traditional six-step rock bolting process to one continuous step. Rock bolting can be realized automatically by pressing button once and the operation time for installing a single bolt can be reduced from 5 to 6 minutes to 3 minutes. The technologies and equipment of automatic spraying support are developed which include high-strength, rapid setting, and deformable surface supporting spraying materials with a tensile strength exceeding 9 MPa, elongation at break exceeding 100%, and a bonding strength exceeding 3 MPa. The spraying system with 6-degree-of-freedom manipulator is developed which can automatically and rapidly spray during roadway driving. The dynamic monitoring technology and system for roadway surrounding rock deformation are developed during driving which can achieve a surface deformation monitoring of roadway in environments with dust, multiple interference, and low illumination. The monitoring accuracy can meet the requirements of the surrounding rock stability evaluation. A new partitioned parallel collaborative rapid driving mode of excavation, spraying, bolting and transport is proposed and a complete set of roadway rapid driving equipment with integrated drilling and anchoring is developed. The displacement and stability of the surrounding rock during the driving process at the Caojiatan Coal Mine in Shaanxi Province are monitored. In terms of time, more than 80% of the surrounding rock displacement had already occurred in 2 to 3 hours after the excavation of the roadway. In terms of space, more than 90% of the surrounding rock displacement had already occurred at a distance equivalent to twice the width of the roadway from the excavation face. Therefore, the roadway surrounding rock displacement caused by rapid driving can be completed in a short time, requiring timely and rapid support. The nearly 6 000 m roadway driving project has been completed in the 10-metre-extra-high fully mechanized mining face of the Caojiatan Coal Mine, and over 60 000 bolts with integrated drilling and anchoring are installed. The time for installing a single bolt, the number of supporting workers, and the labor intensity of workers have been significantly reduced. The driving speed, efficiency, and automation level have been significantly improved. The displacement of the experimental roadway roof is small. The roadway surrounding rock stability is good as well as the support effect. The coal roadway rapid driving technology and equipment with integrated drilling and anchoring have achieved a success in underground field test. It has the ability to achieve a monthly driving footage of 1500 to 2000 m for ultra-large cross-section coal roadways.