(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 according to their numbers. In order to improve the lifting efficiency, when stacking the columns, try to make the three points of column tying point, column foot center and foundation center co-circular arc.
The car crane wire rope will be tied to the steel column and lifting point, and one end of the steel column will be tied with the cable wind rope to assist in lifting, and test lifting will be carried out first when lifting, and lifting can be done only after finding the right 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 40-100mm 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 is checked by latitude and longitude meter, and if there is any deviation, the correction is carried out immediately. In the process of correction, the bottom and the elevation control pad are observed at any time to prevent the horizontal elevation error caused in the process of correction.
Column vertical correction, measurement with two latitudes and longitude meters placed on the vertical and horizontal axis, first align the column bottom vertical flange plate or the centerline, and then gradually look up to the top of the column, such as the centerline deviates from the line of sight, that the column is not vertical, can be commanded to adjust 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. This can be placed in the longitudinal and horizontal axis of the two latitude and longitudinal instruments respectively on one side, deviation from the centerline generally shall not be greater than 3mm.
(Ⅳ) Lifting and correction of steel beam
Steel beam members are delivered to the site and should be assembled first. 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 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 uniform and the steel beam is not deformed as the best state. . And the first beam should be increased by two temporary fixed cable wind ropes, and the beam after the second beam is temporarily fixed by roofing sandals or tie beams.
When lifting the steel beam, the steel column must also be reviewed, at this time the hoist is generally used to pull the wire rope cable for adjustment, and the cable can only be loosened after the beam is installed. The ridgeline of the steel beam must also be controlled so that the centerline of the roof frame and column ends are equivalent deviations so that each span of the steel roof frame is in the same centerline.