The inner diameter of the hole on the steel plate surface of the U-shaped bolt groove is only 1mm larger than the outer diameter of the anchor bolt. The displacement deviation produced by the two bolts is 1mm, so that the center displacement between any bolts in the same bolt group can be guaranteed to reach the construction pre-control target ≤1mm.
Because the precision control of the U-bolt special fixture itself is better, as long as the independent fixture for the special fixture is used by the total station, the accuracy of the anchor bolts inserted into the fixture can be controlled within the design range.
When the special fixture is set up by an independent bracket in advance, the four corners adopt adjustable brackets, and the adjustable brackets on the four corners are adjusted. The level is set on the four sides of the fixture as a reference to make the fixture on a horizontal surface. Then anchor the anchor bolt into the positioning hole which is only 1mm larger than its outer diameter. Take 64mm anchor bolts as an example. The bottom is provided with a jack (used to adjust the level), and the bolt top uses a level or a total station.
The U-bolt top is controlled within the same design level, and the bolt top is fastened with the bolt nut of the bolt so that it does not float upward. The middle and lower parts of the anchor bolts are welded diagonally and horizontally at the bottom with steel bars with a diameter of not less than 1/3 of the bolt diameter so that they do not float left and right. When the fixture is level,