Spherical grid frame of steel structure building -- construction technology
First, set out line, check line
1. Line setting line checking on the top of the column: mark the axis elevation, check the displacement of the top of the column, the installation unit of the grid can only formally install the grid after rechecking the position, size elevation of the supporting point provided by the grid.
2. The installation environment on the ground of the grid shall be leveled lofted, each fulcrum of the grid shall be loaned, indicating the position ball number.
3. Brick blocks at each fulcrum of the net frame ball. The pier can be the supporting point of the steel pipe, a small piece of circular pipe can be added on the brick pier as the ball support under the net frame.
4. Mark the elevation of each fulcrum. If there is a requirement for arching of the grid, it should be reflected at each supporting point.
Spherical grid frame steel grid frame flat installation
1. Ball release: Put the accepted welding ball into the installation node according to the specification number, adjust the stress direction position of the ball. Generally, the circular weld of the horizontal center line of the ball is placed in the equatorial direction. The ribbed side is in the upper half of the lower chord:
2. Pole placement: Before placing the steel pipe pole in accordance with the specified specifications, the specifications dimensions of the pole, as well as the groove weld clearance should be checked. Place the pole between the two balls, adjust the clearance, fix it.
3. The assembly of the plane grid shall start the center line gradually spread out to all sides. First, a closed quadrangle grid shall be formed. Note that cumulative errors should be controlled, negative tolerances are preferred in general grids.
4. Welding of plane grid. Before welding, welding process sequence of grid connection should be worked out to prevent deformation of plane grid.
5. According to the welding procedure, arc starting 20-30mm to the left of the center line of the lower side of the steel pipe welding to the right shall be conducted, welding positions such as inverted welding, main welding, flat welding shall be gradually completed.
6. The ball tube welding shall be carried out by means of obserrated strip welding to prevent biting.
7. After welding the conveyor to the upper center line of the round pipe, continue to weld the arc at 20-30mm forward.
8. After semicircle welding is completed, reverse arc shall be started 20-30mm to the right of the center line of the lower side of the steel tube, welding shall be done to the left. The same process as above shall be done.
Iii. Assembly of the main body of the grid
1. Check accept the size axis deviation of the plane grid, continue to assemble the main grid after the check is correct.
2. Hoist the small assembly unit of one ball four strokes (one ball is the upper string ball, four strokes is the diagonal bar of the net frame) into the upper part of the plane net frame.
3. After the small assembly unit is in place, check the mesh size, vector height, the inclined bar Angle of the small assembly unit. Correct the incorrect position Angle first, install only after qualified correction.
4. If it is found that the length Angle of the rod of small assembly unit are inconsistent during installation, the rod of too long shall be cut off with a cutting machine, then the groove shall be re-opened re-placed for inspection.
5. If a liner rack is required, weld the liner on the ball. However, the spot welding of the small assembly unit should be done with the plane grid frame for the moment, the ding welding can only be done after it is cooperated with the upper chord.