| 摘要 |
PURPOSE: To prevent dangerous shear stresses from being applied to the thread part of a rock bolt made of a fiber-reinforced synthetic resin by forming a flat thread on the surface of the bolt by press-engraving so that the threaded part of the bolt may closely adhere to the thread of a nut over the length of the threaded engagement when tensile forces act on the bolt. CONSTITUTION: A rock bolt (anchor) 5 which is used for the reinforcement, etc., of natural ground is formed of a glass fiber-reinforced epoxy resin, etc., and, at the same time, a flat thread 9 of <=45 deg. in inclined angleαis formed by press-engraving. At the time of forming the thread, care is taken to prevent the cutting of the reinforcing fibers and to make a radial force R as large as possible. In addition, the thread of the bolt may closely adhere to the thread of a nut 12 over the length of the threaded engagement and no stress concentration may occur. Therefore, the fiber-reinforced composite material can sufficiently exhibit its strength characteristic.
|
