Design a square tied interior column to carry 3 k/ft2 of uniform live load and 2 k/ft2 of uniform dead load (including the self weight of the structure), see Figure 1. (a)Use tributary area approach to calculate the factored axial load, Pu, for the interior column. (b) Assume g = 2% and determine the required gross cross-sectional area of the column Ag_req. (c)Select the column dimensions (round the width or depth of the column to the nearest 2 inches). (d) Back solve for the required longitudinal steel area, Ast_req, and select the minimum number of #10 bars placed in all four sides/faces of the column. Use equal number of bars in all four sides of the column. (e)Select the smallest bar size for ties and design for the spacing of the ties. (f) Sketch the final tie arrangement. Note you must meet the requirements in the ACI 318-11 section 7.10.5 (or see McCormac and Brown 9th Ed. Figure 9.4). Place the longitudinal bars at a distance of 3” from the surface of the column to the center of the bars. (g) Calculate the design axial load capacity and verify that it can safely carry the applied factored axial load.

 Design of Axially Loaded Short Columns
Problem 7) Design a square tied interior column to carry 3 k/ft2 of uniform live load and 2
k/ft2 of uniform dead load (including the self weight of the structure), see Figure 1.
(a)Use tributary area approach to calculate the factored axial load, Pu, for the interior
column.
(b) Assume g = 2% and determine the required gross cross-sectional area of the column
Ag_req.
(c)Select the column dimensions (round the width or depth of the column to the nearest 2
inches).
(d) Back solve for the required longitudinal steel area, Ast_req, and select the minimum
number of #10 bars placed in all four sides/faces of the column. Use equal number of
bars in all four sides of the column.
(e)Select the smallest bar size for ties and design for the spacing of the ties.
(f) Sketch the final tie arrangement. Note you must meet the requirements in the ACI 318-11
section 7.10.5 (or see McCormac and Brown 9th Ed. Figure 9.4). Place the longitudinal
bars at a distance of 3” from the surface of the column to the center of the bars.
(g) Calculate the design axial load capacity and verify that it can safely carry the applied
factored axial load.