| 摘要 |
A double pipe type urethane-based fluid injection bolt is provided to have excellent stiffness, and to form a urethane consolidated body in a cylinder regularly by discharging urethane-based fluids all over the longitudinal section of an injection bolt at the same time, thereby to reinforce a tunnel strongly. A double pipe type urethane-based fluid injection bolt(200) comprises an outer tube(110) closed at one end and provided with a fluid injection port(112) at the other end to inject a urethane-based fluid and through holes(114) arranged at regular intervals in the longitudinal direction, an inner tube(120) closed at two ends and inserted at a certain distance from the inside of the outer tube, and a valve(130) installed to the through hole of the outer tube and discharging the urethane-based fluid when the urethane-based fluid reaches the preset pressure. |
