Knowledge

First, the steel structure before the installation of the foundation should do a good job of axis measurement, support surface elevation, the level of the foundation support surface inspection, foot bolts and the length of the extension of the support surface of the weight side and so on.

Before installation should be repeated testing and re-measurement, in line with the following requirements after the handover acceptance procedures, can be carried out steel structure installation.

1. The strength of the foundation concrete meets the design requirements, and the backfill around the foundation is compacted.

2. Before the installation of the basis of the retest, in addition to the inspection of all the acceptance information, should be measured in accordance with the column base test 20%, and should not be less than 5.

Second, when the foundation top or support directly as the support surface of the column, the support surface elevation and horizontal degree should conform to the provisions of table 3, at the same time, the support surface is required to be flat, no honeycomb, hole, slag, loose, crack and pit convex and other appearance defects.

Third, when the foundation top has the pre-buried steel plate as the support surface of the column, the top elevation and level of the steel plate should conform to the provisions of table 3, at the same time, the surface of the steel plate is required to be flat, no weld scar, splash and cement mortar and other dirt.

Four, the Yu Gang Foot and foundation between the steel pad, and then two watering fine stone concrete foundation, steel pad should comply with the following provisions.

1. The area of the steel pad shall be determined according to the strength grade of the concrete, the load borne by the column soles and the fastening tensile force of the foot maggots (anchor Bolt).

2. Steel pad should be set in close to the foot bolt (anchor Bolt) of the column soles stiffening plate or column limb, each foot bolt (anchor) side should be set up 1-2 sets of pads, each set of pads must not be more than 5 pieces, pad and the base top and to the bottom of the foot contact should be smooth and tight.

3. When using a pair of oblique pads, the slope of the two pads should be the same, and its superposition length should not be less than 2/3 of the length of the pad

4. The edge of the pad should remove the flying edge, burr, iron oxide slag, each set of pads should be tightly fitted, steel column correction, foot bolts (anchor Bolt) fastening, two times before watering concrete, pad and column soles, pad and pad should be welded and fixed.

Five, when the use of grouting pad, should comply with the following provisions.

1. The position, quantity and area of the grouting pad shall be determined according to the strength of the non-shrinkage mortar, the load borne by the column soles and the fastening tension of the foot bolt (anchor Bolt).

2. Allowable deviation of elevation, level and position of the grouting pad

3. When using the grouting pad, the non-shrinkage mortar concrete should be used, and the strength grade of the sand paddle test block should be higher than the strength level of the base concrete. The sampling, fabrication, maintenance, testing and evaluation of mortar test blocks shall conform to the provisions of the current national standards.

Six, when the cup mouth base is used, the allowable deviation of the cup mouth size should conform to the provisions of table 5. It is the inevitable factor to ensure the quality of engineering installation to do well the self-inspection, mutual inspection and handover inspection of each process in steel structure engineering.