High-Strength Bolt Connections: Process & Inspection

High-strength bolt connections are a widely used mechanical structure connection method in fields such as construction and bridges. Their construction process and quality inspection methods are crucial for ensuring the stability and safety of the structure.

Firstly, the construction process of high-strength bolt connections includes four steps: material preparation, pretreatment, fastening, and inspection. In the material preparation stage, materials that meet national standards need to be selected, ensuring that the quality and specifications of the materials meet design requirements. In the pretreatment stage, materials need to undergo cleaning, rust removal, and coating treatments to ensure the connection's firmness and tightness. During the fastening stage, specialized tools and equipment must be used, operating according to specified torque or angle values to ensure the bolt connection's fastening force meets the requirements. In the inspection stage, multiple aspects such as appearance inspection, dimensional inspection, torque inspection, strength inspection, and sealing inspection need to be tested and verified to ensure connection quality and reliability.

Secondly, the quality inspection methods for high-strength bolts include appearance inspection, dimensional inspection, torque inspection, strength inspection, and sealing inspection. Among these, appearance inspection mainly checks for cracks, corrosion, etc., on the surface of the connecting parts; dimensional inspection involves measuring whether the dimensions of the connecting parts meet the requirements; torque inspection verifies the bolt connection's fastening force by applying a certain torque; strength inspection examines the strength of the connecting parts through tensile or compression tests; sealing inspection uses instruments like pressure testers to check if the connecting parts have good sealing performance.

Lastly, taking the Tongling Yangtze River Railway-Road Bridge as an example, the main bridge of which is a five-span continuous steel truss cable-stayed bridge, employs two types of high-strength bolts: M24 and M30. During construction, it is necessary to strictly follow the aforementioned construction process and quality inspection methods to ensure the bridge's safety and stability. Additionally, work on acceptance, tightening process, and quality inspection of high-strength bolt connections must be conducted to ensure the smooth progress and high-quality completion of the entire construction process.