Abstract: To realize onetime tunneling and forming as well as rapid excavation of a quasirectangular fullface tunnel in the field of coal mine roadway in China, the cutting mechanism of the tunnel boring machine is investigated for a quasirectangular tunnel with a width and height of 6 m and 4.2 m, respectively. First, the characteristics of multiple tunnelforming technical schemes are analyzed to select a cutting mechanism. The selected mechanism is realized by arranging triplearm cutterheads on the right and left and cutting drums on the top and bottom of the machine. Second, the forming shape of the tunnel is designed according to the actual demands of coal mine tunnels. Third, the structures of the cutterhead and cutting drum are designed, and the cutting picks are selected and arranged. Finally, threedimensional models of the triplearm cutterheads and cutting drums are constructed using SolidWorks, and modal and static analyses are then performed using ANSYS. The following results are obtained. (1) The proposed cutting mechanism can realize onetime tunneling and the formation of a quasirectangular fullface tunnel. (2) This cutting mechanism meets the strength and stiffness requirements of the tunnel without the occurrence of resonance phenomenon. The application results demonstrate that the recommended cutting mechanism has high tunneling efficiency and good application prospects for constructing a quasirectangular tunnel for coal mine roadway.

Key words: coal mine roadway, quasirectangular fullface tunnel boring machine, cutting mechanism; triplearm cutterhead, cutting drum