Fabrication and installation of high strength bolted steel structures
Production and installation of high-strength bolted steel structure for chemical construction technology construction Liu Hao Nanjing Chemical Industry Group Construction Company, Nanjing 210044 High-strength bolt connection Compared with arc welding, it has simple and quick installation, convenient installation and high pressure. The advantages of the crucible cans, etc., have been widely used in the modern one-way construction. The characteristics of the high-strength bolt connection are the number of bolts per node, and there are generally 20 to 30 bolts to form the flatness of the connected members. The concentricity of the vertical holes has higher requirements. If the manufacturing method or the installation sequence is not appropriate, it will be difficult to ensure that the bolts of the connecting plate bolt holes are installed, and the bolts of the other end plates are difficult to be fully loaded. Therefore, in the production of such steel structures, in addition to complying with the rules for the fabrication and installation of steel structures, the billet should be specially marked as follows: 1 The steel material of the steel members should be mechanically cut to ensure the flatness and surface of the steel sheet. Roughness, when the steel plate is thick, gas cutting can be used. After the material is cut off, the slag should be removed and the hole of the high-strength bolt with the shovel 12 should be drilled and formed without flash burrs. A bolt-on hole plate connected by a high-strength bolt, and the two plates are placed in a paired hole by arc welding before drilling. After drilling, apply the mark drum to the non-mooleing blood mark 13 of the two plates respectively. The friction surface of the component after the high-strength bolt connection should be flat. No welding, 6 Peng, 6 thorns are not stained, and the cattle should be protected. Measures to prevent contamination with dirt and oil. 14 diagonal bracing, the end plates of the two ends of the beam are not welded with them at the time of manufacture, and are welded after being installed in place. 2 Installation of steel structure 2.1 The positioning axis, base axis and elevation of the building should be dealt with before the steel structure is installed. The position of the anchor bolts is checked into the hall, and the basic inspection and handling acceptance of the hall are accepted. 2.2 When the column is installed, the clamping axis of each section should be directly drawn from the ground control axis. The installation of the 2.3 steel beam diagonal braces from the axis of the lower column shall be carried out after the steel column is installed in place and meets the acceptance criteria. The specific installation steps are as follows: 1. Connect the two ends of the beam to the two columns with temporary bolts and tighten them. The crane is lifted into position by a crane, and the beam and the end plate are spot-welded by arc welding using a reverse chain adjusting beam, and then fully welded after being tested. A reasonable welding sequence should be selected during welding to prevent or reduce welding distortion. Replace the temporary splicing bolts with the strength bolts from the center of the bolt group. 2.4 The main components such as the column and beam support of the steel structure shall be corrected and fixed after being installed in place. The steel structure installed on the day should form a stable space system. 3 Installation of high-strength bolted joints 3.1 High-strength bolts shall not be used as temporary bolts to prevent damage to the thread caused by the change of the torque coefficient. The number of temporary bolts at each node shall be determined by the installation and the load that may be assumed. 3.2 Installation of high-strength bolts When the friction surface of the component should be kept dry, it is not allowed to work in the rain. It is strictly forbidden to penetrate the bolt with a hammer. If it is not possible to penetrate freely, apply a reamer for dressing. It is strictly forbidden to use the gas-cutting and reaming 3.3 high-strength screw to be tightened into the initial tightening and final tightening. The torque of the initial screwing and the double screwing is equal. The torque value can refer to the high-strength bolt after the initial 82 9 screwing or tamping. Apply the color to the nut and mark it. Then use the special hand to make the final hit, and the shear type 3 strength bolt is declared until the plum head of the tail of the bolt is screwed off. The final screwing of the large hexagonal high-strength bolt shall be finalized according to the construction torque value specified in the specification 291, page 3.4.10 of the 291 page. After the final screwing, mark the 3.4 bolt on the nut with another color. When screwing and screwing, it should be applied in the order of the order. Generally, it should be tightened outwardly from the center of the bolt group, and the first step is to be screwed. It should be completed on the same day. Practice has proved that this method is effective. The pipe gallery and equipment frame steel structure of Yangzi Petrochemical's 200,000 hydrogenated gasoline aromatic extraction device adopts twisted high-strength bolt connection. The above method has achieved twice the result with half the effort. Not only does it guarantee quality, but it also saves a lot of man-hours. Received date 1999 this 09 Towel Shelf,Barhroom Towel Shelf,Villa Bathroom Towel Rack,Towel Shelf Rose Gold Kaiping Jenor Sanitary Ware Co., Ltd , https://www.jenorsanitary.com