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D13.D.4 Columns

Reinforcement for columns of rectangular or circular cross section can be calculated. The flexibility of columns can be evaluated in two ways.

  • In the case of linear analysis (i.e., the PERFORM ANALYSIS command), the effective length is evaluated using the ELY and ELZ parameters, conforming to provisions of SP5 2.13330.2011.
  • If a P-DELTA or NONLINEAR (i.e. nonlinear geometry) analysis is performed, the values of the ELY and ELZ parameters should be close to zero (e.g., ELY = ELZ = 0.01).

Longitudinal reinforcement for columns is calculated only for the strength condition. Longitudinal forces and bending moments in relation to local axes Y and Z are taken into account in longitudinal reinforcement calculations.

For rectangular columns, the following output is generated:

  • column number;
  • column length and cross-sectional dimensions;
  • distance of centroid of each longitudinal bar from the nearest edge of the cross-section;
  • concrete class;
  • longitudinal reinforcement class;
  • range of longitudinal reinforcement bar diameters assumed in calculation;
  • diameter of longitudinal reinforcement bars obtained in calculation;
  • total quantity of longitudinal bars;
  • quantity of longitudinal bars at each cross-section edge, directed parallel to the local axis Y ;
  • quantity of longitudinal bars at each cross-section edge, directed parallel to the local axis Z.

In nine columns of the table under the heading LONGITUDINAL REINFORCEMENT, the following output is presented:

  • Section – distance of the section from the “start” of the column, mm;
  • Astot – total cross-sectional area of longitudinal reinforcement, sq.cm;
  • Asy – cross-sectional area of longitudinal reinforcement bars at each edge of section, directed parallel to the local axis Y , sq.cm;
  • Asz – cross-sectional area of longitudinal reinforcement bars at each edge of section, directed parallel to the local axis Z , sq.cm;
  • Percent – reinforcement percentage in the section;
  • Nx, Mz, My – respective values of longitudinal force and bending moments in relation to the local axes Z and Y , determining cross-sectional area of longitudinal reinforcement;
  • Load.N. – number of loading version, determining cross-sectional area of longitudinal reinforcement.