Construction plan for steel structure (3)

(Ⅲ) Lifting and alignment of steel columns

● When unloading the steel column materials, the steel column members are positioned one by one according to the construction drawings their numbers. To improve the lifting efficiency, when stacking the columns, try to make the three points of the column tying point, column foot center and foundation center co-circle.

● Tie the steel column and the lifting point with the steam crane wire rope, and tie one end of the column with the cable wind rope to assist in lifting. When lifting, the crane will slowly lift the tied column 20cm off the ground, check the sling solid and crane stability, while opening the slewing brake, then the steel column down to 40-100 mm from the installation surface, align the datum line, command the crane down, the column into the anchor bolt temporary fixed, steel column by the initial correction, to be verticality deviation control within 20mm before the crane off the hook, the steel column The perpendicularity of the steel column will be checked with a latitude and longitude meter and corrected immediately if there is any deviation. During the correction process, observe at any time whether the bottom and the elevation control pad are out of the air to prevent the horizontal elevation error caused during the correction process.

● Vertical correction of the column, measurement with two latitudes and longitude meters placed on the vertical and horizontal axis, first align the column bottom vertical flange plate or the center line, and then gradually look up to the top of the column, such as the center line deviates from the line of sight, that the column is not vertical, you can command the adjustment of the pull rope or support, available knocking and other methods to make the column vertical. In practice, often put rows of columns are erected, and then corrected. At this time, two longitudinal and latitudinal instruments can be placed on one side of the vertical and horizontal axis respectively, and the deviation from the center line should not be greater than 3mm in general.

(Ⅳ) Lifting and correction of steel beam

● The steel beam members should be assembled first when they are delivered to the site. When the steel beam needs to be turned over and lifted, two points are used to turn over and lift the plate, and short steel pipes and square wood are used to temporarily assist in lifting the plate. After the steel beam is turned over and put into position, it is necessary to carry out several test lifts and re-tie the slings in time. When the test lift is carried out, the crane must rise slowly, so that the force at each lifting point is even and the steel beam is not deformed. . And the first beam should be increased by two temporary fixed wind ropes, and the beam after the second beam is temporarily fixed by roofing sandalwood or tie beam.

When lifting the steel beam, the steel column must also be reviewed, and the hoist is usually used to pull the wire rope cable for adjustment. The ridge line of the steel beam must also be controlled. So that the roof frame and column ends of the centerline equivalent deviation, so that each span of steel roof frame are in the same centerline.