Notes on steel structure design

Notes on steel structure design

Once you get the operation chart, don’t blindly model and calculate.First, conduct comprehensive analysis, communicate with architectural designers, and fully understand the various conditions of the project (function, type selection, etc.).


Second, the pre-processing before modeling and calculation should be done well.For example, the calculation of load should be accurate and cannot be estimated.Input according to the construction practice or use requirements.


Third, in the process of structural modeling, it is necessary to understand the meaning of each parameter and not to modify the parameters blindly, and the modification should be based on.


4. In the calculation, the economy under the technical conditions should be fully considered.It is not allowed to increase the amount of reinforcement or increase the cross-section of members at will.This should be taken as one of our design concepts.


After the computer calculation of five beams, columns and slabs, a large number of adjustments and modifications should be carried out, all of which should be based on the check calculation sketch and other data.Specifically, there are the following centralized modifications or precautions:


  a. Beam:

  1.The elevation of the beam (whether to determine the elevation of the bottom of the beam and the upward turning of the beam, etc.)

  2.The bearing negative reinforcement of beam shall not be too sparse, and it shall be densified artificially.

  3.The span number of beams should be checked.

  4.The type and grade difference of reinforcement shall be reduced as far as possible (≤ grade 2)

  5.The beam with awning and other overhanging components should be strengthened (the stirrup can be densified and the anti torsion reinforcement can be set here)

  6.The placement of reinforcement in the beam must meet the requirements of clear distance, especially the clear distance of upper reinforcement (≥ 1.5D or 30mm)

  7.When encountering the well shaped beam (with primary and secondary relationship) of computer calculation results, it is necessary to distinguish the primary and secondary relations, and mark the support reinforcement at the main beam support

  8.For the coupling beam placed on the edge beam, the support reinforcement near the side beam should not be too large, but should be reduced, so as to reduce the torque to the edge beam

  9.There is a relationship between the primary and secondary beams, and there is also a difference in the beam section. The secondary beam should be appropriately reduced.


  b. Column:

  1.Meet the requirements of axial compression ratio (≤ 0.9)

  2.The section of the column should be rectangular column.

  3.Setting of constructional column (check p72 of code for seismic design of buildings)


  c. Plate:

  1.The negative reinforcement should not be too fine, but can be replaced by larger diameter reinforcement, which can avoid being stepped down during construction

The diameter of the reinforcement should not be too sparse, otherwise it is not stressed or easy to crack.

  2.The elevation and slab profile shall be indicated in the structural plan.

  3.The reinforcement of roof slab must be fully pulled through.

  4.The reinforcement of slab should be expressed clearly and should not be speculated by the construction personnel.

  5.In the structural plan, the position and size of awning, balcony and cornice shall be indicated, and the detail drawing shall be drawn.


  d. Foundation:

  1.It is not allowed to mix deep foundation with shallow foundation.

  2.When calculating the foundation load, never omit to calculate the load (including the load weight of the bottom wall, etc.)

  3.The elevation of Foundation (including ground beam, bearing platform, etc.) shall meet the passing of upper pipeline, and generally 300 mm shall be reserved on it.

Post time: Jul-03-2020