1、 Column unloading method of steel structure workshop

When the column must be strengthened or replaced under unloading condition, the method of "joist replacing column" should be adopted.

2、 Reinforcement method of steel column for steel structure workshop

1. Section of reinforced column. Generally, the section of reinforced column is made of steel plate or section steel, and connected with the original column by welding or high-strength bolts to form a whole.

2. Add support. The support is added to reduce the free length of the column and improve the bearing capacity. The stability of the column is improved with the same section size.

3. Change the calculation diagram to reduce the external load or internal force of the column.

4. The bearing capacity of steel columns can be improved obviously by wrapping reinforced concrete around them.

3、 Reinforcement method of steel structure workshop column base

1. Reinforcement method for insufficient thickness of column base plate

In order to reduce the calculated bending moment of the bottom plate, the stiffener of the column base is added. Concrete is poured between the steel sections of the column base to make the bottom plate of the column base become a rigid block. In order to increase the cohesive force, the paint and rust on the surface of column base shall be removed.

2. Reinforcement method for insufficient anchorage of column base

Add additional anchor bolt. When the concrete foundation is wide, it is adopted. Drill holes on the concrete foundation, insert additional anchor bolts, pour epoxy mortar or sulfur mortar (hole diameter is anchor bolt diameter "plus 20 mm, depth greater than 30 d), and wrap the whole column base with reinforced concrete. The new reinforcement shall be extended into the foundation and welded with the original reinforcement in the foundation.

4、 Test method for bearing capacity of steel structure workshop column reinforcement

In the reinforcement calculation under load state, the important problem is whether the stress can be redistributed after reinforcement, that is, whether the original stress can be distributed to the new reinforced member section after reinforcement. If it can be redistributed, the sum of the new and old loads can be evenly distributed to the new and old sections, otherwise the original load will still be borne by the original section, The new load is shared equally by the new and old sections (i.e. the total section after reinforcement).