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Shell Reinforcement Check

In CSI, it is not possible to specify the actual reinforcement in shells.

To check reinforcement in shells, the user can define special groups in the CSI model and add elements to them for which reinforcement should be checked.

<aside> 💡 See also: What is a Group?

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The group name should be set as АП_В1-12-200_Н2-16-150:

• АП — identifier that the group is used in reinforcement check.

• В1, В2, Н1, Н2 ****— rebar location: top and bottom bars in the direction of local axes 1 and 2.

  Different directions are separated by an underscore _.

• 12-200 — diameter and distance between bars in mm.

  Parameters in the group are separated by a dash -.

  

  Top longitudinal reinforcement of shells

  

  Bottom longitudinal reinforcement of shells

Summary of the Reinforcement Design Process

Columns

Geometric dimensions of sections, cover layers and reinforcement location are requested from the CSI model.

For each section, the plugin creates an interaction surface using reinforcement diameters from 6 to 40 mm according to the range (6, 8, 10, 12, 14, 16, 18, 20, 22, 25, 28, 32, 36, 40 mm).

Each section is considered for the action of forces from all combinations. The forces take into account the factor for longitudinal bending.

If the section DC ratio is greater than the limit value (1.0), then the next diameter is taken.

In the output section, the diameters of all longitudinal bars are replaced. All bars of the output section have the same diameter. The number and position of bars remains the same as specified in the CSI model.

If it is possible to find a diameter at which the section DC ratio is less than 1.0, then a crack width calculation is performed.

The crack width calculation is performed in the following order:

• The interaction surface, plotted taking into account the tensile strength of concrete, determines the possibility of cracking and the area of tensile concrete in the section without crack.
• If the acting forces exceed the cracking forces, then the deformations of the section with a crack are calculated for the action of forces from long-term and full loads, as well as for the action of cracking forces (to calculate the $\psi_s$ factor).