What is the allowable deviation of verticality of steel structure column installation?
Allowable deviation of verticality of steel structure installation column axis:
Simple column, h 10m, deviation H/ 1000, and not more than 25mm；;
For multi-section columns and single-section columns, the deviation is H/ 1000 and not more than 10, and the column height is not more than 35mm.
Extended data:
Performance indicators:
1, strength
The strength index of steel consists of elastic limit σe, yield limit σy and tensile limit σ u, and the design is based on the yield strength of steel. High yield strength can reduce structural weight, save steel and reduce cost.
Tensile strength σu is the maximum stress that steel can bear before it is destroyed. At this time, the structure loses its service performance due to large plastic deformation, but the structure deforms without collapsing, which meets the requirements of the structure to resist rare earthquakes. The value of σ u/σ y can be used as a parameter of steel strength reserve.
2. Plasticity
The plasticity of steel generally refers to the property of obvious plastic deformation without fracture after the stress exceeds the yield point. The main indexes to measure the plastic deformation ability of steel are elongation δ and area shrinkage ψ.
3, cold bending performance
The cold bending performance of steel is a measure of crack resistance of steel when plastic deformation occurs during bending at room temperature. The cold bending performance of steel is to test the bending deformation performance of steel under the specified bending degree through cold bending test.
4. Impact toughness
The impact toughness of steel refers to the ability of steel to absorb mechanical kinetic energy in the process of fracture under impact load, and it is a mechanical property to measure the resistance of steel to impact load, which may lead to brittle fracture due to low temperature and stress concentration. The impact toughness index of steel is generally obtained by the impact test of standard samples.
5. persistence
There are many factors that affect the durability of steel. First of all, the corrosion resistance of steel is poor, so protective measures must be taken to prevent steel from rusting.
Protective measures include: painting and maintaining steel regularly, using galvanized steel, and taking special protective measures in strong corrosive media such as acid, alkali and salt. For example, the offshore platform structure adopts "anode protection" measures to prevent the jacket from corrosion, and the zinc ingot is fixed on the jacket, so that the seawater electrolyte will automatically corrode the zinc ingot first, thus protecting the steel jacket.
Secondly, because the failure strength of steel under high temperature and long-term load is much lower than that under short-term load, it is necessary to measure the durability strength of steel under long-term high temperature. Steel will automatically harden and become brittle with the passage of time, which is the phenomenon of "aging". The impact toughness of steel under low temperature load should be tested.