Project Overview: This project is located in Jilin Province. The total length of the canopy of the Harahai toll station is 35 meters, the maximum width is 16.6 meters, and the construction area is 581 square meters. The grid frame of this project adopts the form of bolted ball node quadrangular cone grid frame, and the grid frame supports Form: The upper chord supports longitudinally opposite sides. The projection area of the grid is 581 square meters, and the maximum grid size is 1.5×2.3 meters.

Material and technical requirements:

①. High-frequency electric welded steel pipes are used for rod steel pipes. The high frequency electric welded steel pipe adopts Q235B, and its tensile strength, elongation, yield point, cold bending and limit content of carbon, sulfur, and phosphorus should all meet the requirements of "Carbon Structural Steel" (GB700-88).

② Bolt ball and casing are made of No. 45 steel, and their tensile strength, elongation, yield point, impact toughness, hardness and limit content of carbon, sulfur, and phosphorus should all meet the "Quality Carbon Structural Steel Technical Conditions" GB699-88 stipulates that bolts are ball forged.

③. High-strength bolts and fastening screws are made of 40Cr steel, and their tensile strength, elongation, yield point, impact toughness, hardness and chemical composition should meet the requirements of "Technical Conditions for Alloy Structural Steels" GB3077-88, and should also meet " Steel Grid Bolt Spherical Joints" JG10-1999, "Steel Grid Inspection and Acceptance Standards" JG12-1999, "Bolt Technical Conditions" GB38-76, "Fastener Mechanical Properties" GB3098.1～GB3098.3-SZ, "Fastener Surface Defects" GB5799.1-GB5799.3-86, "Basic Dimension of Common Thread-Coarse Common Thread" GBI 9651.

High-strength bolts use performance grade 10.9, screw thread tolerance according to GB197 6g grade, the hardness of the screw after heat treatment should be HRC36-42.

All high-strength bolts must be 100% quality inspected and recorded and filed. They can be used after passing the inspection.

④ The cone head, sealing plate, and bearing adopt Q235B, and its tensile strength, elongation, yield point, cold bending and limit content of carbon, sulfur, and phosphorus should meet the requirements of "Carbon Structural Steel" GB700-88 .

⑤, purlins and other non-stressed components adopt Q235B, and their specific requirements must also meet the requirements of GB 700-88.

⑥ Welding material: base material is Q235 steel, H08-A welding wire is used for automatic welding of the electrode, and the performance of the welding wire must conform to the regulations of GB1300-77. When manual welding is used, E4315 or E4316 type electric welding electrode is used. .

The 45# steel bolt ball is welded with Q235 steel. Due to the different steel grades, in order to ensure the welding quality, a dynamic load test should be performed before batch welding to achieve an equal strength connection. Use low-hydrogen type E5015 or E5016 welding rods. Small size electrodes should be prepared before welding. Heating equipment and fixtures, fill the hole on the ball with asbestos rope (to prevent the hole from being oxidized), the welded steel plate should be cut on both sides, and the ball should be preheated to 30°C before welding. After welding, it should be tempered and rise to 400°C. , Keep the temperature for half an hour, bury it in quicklime and cool slowly.

The connection between the cone or the sealing plate and the steel pipe must be automatically welded, and the weld adopts a fully penetrated grooved V-shaped butt weld form to ensure the welding strength of the connecting weld and the connected rod section.

⑦ Anti-corrosion: Derusting and painting of the grid frame is carried out after the production quality inspection is qualified, and the surface derusting meets the requirements of national standards. The rust removal quality grade is Sa2.5, the primer is epoxy iron red with a thickness of 30 μm, and the intermediate paint is epoxy mica with a thickness of 50 μm.

Project contract scope: Mainly responsible for the processing, production, transportation and on-site installation of the grid.


Grid, grid structure, grid engineering, grid processing, grid company preferred Jiangsu Huahai Steel Structure Co., Ltd., Xuzhou grid steel structure processing base, focusing on stainless steel grid, carbon steel grid, bolt ball grid, dry Manufacturers of coal shed grids, gas station grids, solar photovoltaic brackets, light steel villas and steel structures. Huahai Grid "contracts, keeps promises, and abides by promises". The company has Xuzhou Huahai stainless steel grid processing plant, steel structure manufacturing plant, Jiangsu Huahai Steel Grid Design Institute, and Jiangsu Suhai Industry and Trade Co., Ltd. under its jurisdiction.