Steel structure engineering common bolt connection inspection requirements
The fastener connection joints of the steel members shall be tightly attached to the connecting steel plates, and the appearance shall be neatly arranged. After the inspection is passed, the fastening construction shall be carried out. The bolts are divided into eleven grades according to grades: 3.6, 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, 9.8, 10.9, 12.9, etc., of which 8.8 grades are high-strength bolts, and grades 8.8 or less (excluding grades 8.8) are ordinary. bolt.
The number of temporary bolts installed and installed at each node shall be determined according to the load applied during the installation process, and shall comply with the following provisions: not less than 1/3 of the total number of mounting holes; temporary bolts shall not be less In 2 pieces.
The bolts in the permanent ordinary bolt connection shall not be padded with two or more washers at one end, and the large nuts shall not be used instead of the washers. The fastening shall be firm and reliable, and the exposed thread shall not be less than 2 buckles.
For bolts and anchor bolts that are designed to be loose, the nuts (double nuts) or spring washers with anti-loosening devices should be used, or the anti-loose measures should be taken by manual methods (such as the bolts with exposed bolts).
For bolted connections that are subjected to dynamic loads or important parts, spring washers should be placed as required by the design. Spring washers must be placed on one side of the nut. For the I-beam and channel steel, the inclined washer should be used as much as possible so that the support surface of the nut and bolt head is perpendicular to the screw.
The storage and transportation of fasteners should meet the following requirements: storage should be moisture-proof, rain-proof, dust-proof, and stored according to type and specification; should be handled gently to prevent impact, damage to packaging and damage threads; For the record, the remaining fasteners should be used for recycling and storage;
Specification for bolts and nuts for steel structure engineering
The types, specifications and performances of high-strength bolted joints, ordinary bolts and other standard parts such as nuts and washers, such as nuts and washers, shall comply with current national product standards and design requirements.
Number of inspections: full inspection.
Inspection method: Check the quality certificate of the welding material, Chinese mark and inspection report.
The torque coefficient of the high-strength large hex head bolt connection pair, the tightening force of the torsion-shear type bolt connection pair, and the minimum tensile load of the ordinary bolt shall be re-inspected according to national standards.
Number of inspections: 8 bolts per specification.
Inspection method: Check the re-inspection report.
High strength large hex head bolt fastening check.
Check quantity: 10% of the number of bolts per node, but many of them are subjected to torque sampling.
Inspection method: Tap the bolt one by one with a small hammer of 0.3 to 0.5 to check the degree of fastening to prevent leakage. If there is a contact that does not meet the requirements, it should be expanded by 10% for spot check. If it still does not meet the requirements, the entire node should be re-tightened and inspected. Torque check should be done after 1 hour and should end after 24 hours.
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