Design of Anchorage to Concrete ACI 318-11 Appendix D

The design of anchorage to concrete is governed by ACI 318-11, which provides guidelines for the design of various types of anchors. Appendix D of ACI 318-11 specifically deals with the design of anchorages to concrete using the strength design method. Here is a general overview of the design process according to ACI 318-11 Appendix D:

Determine the design load: Identify the applied load that the anchor needs to resist. This could include tension, shear, or a combination of both.

Identify the anchor type: ACI 318-11 Appendix D provides design guidelines for various types of anchors, such as headed bolts, headed studs, hooked bolts, and post-installed anchors. Determine the anchor type that is suitable for your specific application.

Concrete capacity: Calculate the concrete capacity using the appropriate equations provided in ACI 318-11. The capacity depends on factors such as concrete strength, edge distance, spacing, and embedment depth.

Steel capacity: Calculate the steel capacity of the anchor based on the applicable equations in ACI 318-11. The capacity depends on factors such as anchor diameter, effective embedment depth, and anchor material properties.

Design strength: Compare the design loads to the concrete capacity and steel capacity. The design strength should be equal to or greater than the design load for the anchor to be considered adequate.

Allowable loads: Calculate the allowable loads for the anchor by dividing the design strength by appropriate safety factors specified in ACI 318-11.

Considerations for cracked concrete: ACI 318-11 provides additional provisions for anchors in cracked concrete. The design should consider the effects of concrete cracking and take into account factors such as crack width, anchor spacing, and edge distance.

Edge effects: Consider the edge distance requirements provided in ACI 318-11. Anchors placed close to the concrete edge may have reduced capacity due to edge effects, and additional checks or modifications may be necessary.