Abstract: A tension meter of an anchor rod with constant resistance and large deformation comprises a pull rod and a hollow jack (13). The meter further includes: a rotation device for controlling the rotation angle of the hollow jack (3); a lifter for adjusting the height of the hollow jack (13) and the rotation device; a first hydraulic pump (1) for driving the hollow jack (13), wherein the hollow jack (13) is fixed on the rotation device mounted on the lifter. The meter has a large measurement range and a high load capacity.

Abstract: A constant-resistance and large deformation anchor cable and a constant-resistance device are provided. The constant-resistance and large deformation anchor cable comprises cables (7), an anchoring device (13), a loading plate (12) and clipping sheets (4). The upper end of cables (7) is fixed on the anchoring device (13) and the loading plate (12) by clipping sheets (4). The constant-resistance and large deformation anchor cable also comprises a constant-resistance device, and the constant-resistance device comprises a sleeve (8) and a constant-resistance body (5). The sleeve (8) is a straight tube. The constant-resistance body is conical, and the diameter of the lower end of the constant-resistance body is bigger than the diameter of the upper end of the constant-resistance body. The inner diameter of the sleeve (8) is smaller than the diameter of the lower end of the constant-resistance body.

Abstract: A constant-resistance large-deformation anchor rod includes a rod body (6), a tray (3), a nut (2), and a constant-resistance device (4). The constant-resistance device (4) is formed into a cylindrical structure, and the inner surface of the constant-resistance device (4) and the outer surface of the rod body (6) are both formed with thread structures. The constant-resistance device (4) is sleeved at the tail of the rod body (6), and the tray (3) and the nut (2) are sequentially sleeved at the tail of the constant-resistance device (4). The nut (2) is in threaded connection with the constant-resistance device (4). The constant-resistance large-deformation anchor rod in the invention can be automatically stretched when the tunnel surrounding rock deforms largely, and keep the constant working resistance.

Abstract: A system and method for testing gas migration process in the coal and rock mass are disclosed. The method includes the following steps: selecting a cylindrical coal sample, applying an axial pressure and a radial pressure to the coal sample under a sealing state, and/or increasing temperature, to desorb gas absorbed by the coal sample; guiding the gas desorbed from the coal sample by a guiding passage, detecting gas flow rate and pressure, analyzing gas composition and content, and achieving a data statistics. The method provides a theory and data basis for researching the forming and occurring process of gas outburst accident in coal mine. The system is simple and easy to use, and is suitable for migration research of the gas absorbed in the deep coal-rock mass.

Abstract: A system and method for testing gas migration process in the coal and rock mass are disclosed. The method includes the following steps: selecting a cylindrical coal sample, applying an axial pressure and a radial pressure to the coal sample under a sealing state, and/or increasing temperature, to desorb gas absorbed by the coal sample; guiding the gas desorbed from the coal sample by a guiding passage, detecting gas flow rate and pressure, analyzing gas composition and content, and achieving a data statistics. The method provides a theory and data basis for researching the forming and occurring process of gas outburst accident in coal mine. The system is simple and easy to use, and is suitable for migration research of the gas absorbed in the deep coal-rock mass.