2. Alternative Method for Out-of-Plane Slender Wall Analysis Applicability
Precast concrete walls can be analyzed using the provisions of Chapter 11 of the ACI 318-14. Most walls, and especially slender walls, are widely evaluated using the “Alternative Method for Out-of-Plane Slender Wall Analysis” in Section 11.8. The requirements of this procedure are summarized below:
• The cross section shall be constant over the height of the wall ACI 318-14 (11.8.1.1(a)) • The wall can be designed as simply supported ACI 318-14 (11.8.2.1) • Maximum moments and deflections occurring at midspan ACI 318-14 (11.8.2.1) • The wall must be axially loaded ACI 318-14 (11.8.2.1) • The wall must be subjected to an out-of-plane uniform lateral load ACI 318-14 (11.8.2.1) • The wall shall be tension-controlled ACI 318-14 (11.8.1.1(b)) • The reinforcement shall provide design strength greater than cracking strength ACI 318-14 (11.8.1.1(c)) • Pu at the midheight section does not exceed 0.06 fc’Ag ACI 318-14 (11.8.1.1(d)) • Out-of-plane deflection due to service loads including PΔ effects does not exceed lc/150 ACI 318-14 (11.8.1.1(e))
ACI 318 requires that concentrated gravity loads applied to the wall above the design flexural section shall be assumed to be distributed over a width: | ACI 318-14 (11.8.2.2) |
a) Equal to the bearing width, plus a width on each side that increases at a slope of 2 vertical to 1 horizontal down to the design section. | |
b) Not greater than the spacing of the concentrated loads. | |
c) Not extending beyond the edges of the wall panel. | |
| ACI 318-14 (11.8.2.2) |
