One interesting part of being a field engineer for Simpson Strong-Tie is having the opportunity to see how different structural engineers may take different approaches to similar designs. We at Simpson Strong-Tie have come to appreciate these different approaches and embrace this phenomenon by providing multiple resources to aid in the completion of a design. This is very apparent when it comes to the design of post-installed anchors.
As many of you reading this know, the design requirements for anchoring in concrete to transmit structural loads are provided in ACI 318-19, Chapter 17 – Anchoring to Concrete. The equations featured in Ch. 17 of ACI 318 are plentiful and lengthy, making it a tedious task for any structural engineer performing hand calculations in accordance with this standard. In response, Simpson Strong-Tie has created multiple software solutions to aid in the design of these anchors, such as the Anchor Designer™ Software and Post-to-Foundation Designer. These two software platforms are a great resource for any structural engineer to have. However, for single-anchor design conditions, some engineers still prefer allowable load tables to determine the capacity and required embedment of post-installed anchors.
Listening to the needs of our engineering customers, Simpson Strong-Tie has produced both Allowable Stress Design and Strength Design load tables for many of our high-strength post-installed anchoring solutions. This article will introduce these anchor allowable load tables in the form of our Technical Engineering Bulletin (TEB) document for anchors. Additionally we will include design examples utilizing the load tables and highlight important information to note while using these load tables. [For the design examples, see the complete article on the Structural Engineering blog.]
The three most popular Technical Bulletins for Anchor Design support both our adhesive and mechanical post-installed anchor solutions. These comprise the following bulletins:
- TEB-A-SET3G23 – SET-3G™ Design Information — Concrete (SET-3G high-strength epoxy adhesive)
- TEB-A-THD23 – Titen HD® Design Information — Concrete (Titen HD Heavy-duty screw anchor)
- TEB-A-STB2-23_R1 – Strong-Bolt® 2 Design Information — Concrete (Strong-Bolt 2 wedge anchor).
Load tables that you will find in all TEB documents include the following:
- Tension Design Strength in Normal-Weight Concrete. Tension Design Strength is also known as Strength Design, which uses the strength reduction factor, ø, based on using a load combination from ACI 318-14 Section 5.3.
- Allowable Tension Loads in Normal-Weight Concrete for Static, Wind and Seismic loads. Loads provided in these Allowable Tension Load tables are based on tension design strengths that are converted to allowable tension loads using a conversion factor that is based upon a load combination dependent on the loading condition (static, wind, or seismic).
Some specific conditions unique to each product include, but are not limited to:
- Shear Design Strengths and Allowable Shear Loads for both the Titen HD® and Strong-Bolt® 2 mechanical anchors.
- Load tables for both the soffit and topside of normal-weight concrete-filled profile steel deck assemblies for the Titen HD heavy-duty screw anchor.
- Shear Design Strengths and Allowable Shear Loads for 1/4”- and 3/8”-diameter Titen HD anchors with 1” Nominal Embedment Depth.
Important Notes for Using Anchor Load Tables
Certain design assumptions and conditions are needed to produce these anchor load tables. It’s important to note that these design assumptions and conditions are stated in the load table icons on page 2 of the TEBs and in the table footnotes for each corresponding table. The footnotes of each table further explain how the Design Strength (Strength Design) capacities were calculated and what factors were used to calculate the Allowable Load capacities. We recommend that designers review all footnotes when using any of the load tables.
Conclusion
It’s apparent based on the two design examples that there are multiple ways to use the design tables included in Simpson Strong-Tie® Technical Bulletins for anchor design. Some takeaways are that it’s always important to confirm that the information contained in the TEBs is being followed correctly by using the appropriate table and carefully examining the conditions and footnotes in the tables to ensure they are appropriate for each given design condition. Having these design tables offers a quick and efficient way to design anchoring solutions in accordance with the appropriate design standards. Happy Anchor Designing!
The article, Allowable Load Tables at Your Service — A Look at the Technical Engineering Bulletin (TEB) for Anchors, appeared first on Simpson Strong-Tie Structural Engineering Blog. To sign-up to receive the Engineering Blog in your inbox, go to seblog.strongtie.com/subscribe. Copyright © 2024 Simpson Strong-Tie Company Inc. All Rights Reserved