The method of slurry cushion plate in the center seat of steel structure column installation saves labour and time. The construction accuracy can be controlled within 2 mm, and the comprehensive benefit can be increased by more than 20%. The construction steps are as follows:
(1) The steel column foundation construction is carried out according to the construction drawings (the same as the usual construction method). The base surface is 30-50 mm higher than the installation standard of the steel column bottom surface, so as to prepare for the placement of the central base slurry cushion plate.
(2) According to the weight Q of steel column, bolt pretension F and compressive strength P of foundation concrete, the minimum compressive area Amin is calculated.
(3) Square or circular central cushion plate made of steel plate with thickness of 10 and 12 mm should not be less than twice the minimum confined area of Amin.
(4) Pulp on the completed foundation and place the central cushion board. During construction, it is necessary to measure accurately with horizontal ruler, level gauge and other tools to ensure the level of the central cushion plate, to ensure that the center of the cushion plate is consistent with the installation axis, and to ensure that the upper elevation of the cushion plate is consistent with the installation elevation of the bottom of the steel column.
(5) When the strength of the slurry concrete is over 75% of the designed strength, the steel column is hoisted. The lifting of steel columns can be carried out directly, and the leveling and alignment can be carried out only by adjusting the anchor bolts.
(6) Secondary grouting with non-shrinkage concrete or micro-expansion concrete. Secondary grouting was carried out.