Important design considerations and traditional approaches related to the design of a five-story wood-framed structure over a two-story concrete or masonry podium were addressed in Part 1 of this series (January 2017, STRUCTURE). The goal of this article is to help engineers better understand flexibility issues associated with these types of structures and how they can affect the design process. …
What does stiffness have to do with strength? Well, engineers may remember learning about composite beam design, column design, or beams with compression reinforcing. Courses that included these topics introduced the “n” Factor. That is the factor that defines the ratio of the moduli of elasticity between materials. It is used in calculations to convert the stiffness of different materials to a common one. This was the foundation for understanding that stiffness plays a role in the distribution of forces in a section.
The masonry code, TMS 402/ACI 530/ASCE 5 Building Code Requirements for Masonry Structures (TMS 402), requires that reinforced masonry walls designed using Strength Design (SD) procedures be analyzed for second-order effects. This article discusses the design of reinforced, load-bearing masonry wall systems under the action of combined vertical and out of plane loading using the new moment magnifier provisions in TMS 402 referenced in the 2015 International Building Code (IBC). …
For centuries, bridges and other structures were big, bulky, visually disruptive hulks. Stone, iron, and concrete made them symbols of strength and stability. Solid construction helped people feel more confident about crossing or entering them. …
Nationwide, there has been an increase in the demand for multi-story mixed-use and multi-residential structures. Common configurations include up to five stories of residential use over retail, commercial, office, and parking occupancies, similar in configuration to the building shown in Figure 1. Podium designs are one way to maximize the number of stories, increase unit density, and lower construction costs. This article covers important design considerations and traditional approaches related to the design of a five-story wood-framed structure over a two-story concrete or masonry podium. …
Anchor channel systems are cast into a concrete member. They are used to attach both structural and nonstructural components. Attachment of nonstructural components, such as curtain wall, is a typical anchor channel system application. Traditionally, anchor channel systems have been designed using manufacturer’s data and allowable stress design. Anchor channel systems can now receive recognition under the International Building Code (IBC) for design with strength design provisions. …