Sleeper screws are connecting parts of steel structure. According to the bearing capacity, they can be divided into ordinary bolts and sleeper screws. The following will introduce the precautions in the construction of sleeper screws.
1. For the bolted connection of dynamic load or important parts, the spring washer should be placed according to the design requirements, and the spring washer must be set on the side of the nut.
2. The installation of the sleeper screws should be able to freely penetrate the hole, and it is strictly forbidden to forcibly penetrate. The hole diameter of the connecting steel plate of sleeper screws is slightly larger than the diameter of the bolt, and must be formed by drilling.
3. The connection forms of sleeper screws are usually divided into friction connection, tension connection and pressure connection. Among them, friction connection is the basic connection form that is widely used at present.
4. The installation sequence of sleeper screws: It should be carried out from the part with high rigidity to the unconstrained free end. The sleeper screws on a joint should be tightened one by one from the middle of the bolt group to the four sides for the initial screwing, re-twisting and final screwing. Each screwing should be marked with different colors of paint to prevent leakage. The initial screwing, re-twisting and final screwing of the sleeper screws in the same joint should be completed within 24h. If there is no specified design, it should be carried out according to the construction process sequence of tightening the sleeper screws first and then welding (that is, bolting first and then welding).