This article identifies common errors that structural engineers make when performing seismic design and calculations. The intent is to help engineers avoid those errors and misapplications. This article is written in checklist format such that an engineer can verify adequate self-knowledge, as well as review the work of others on a project. …
Cold-formed steel (CFS) trusses can be an economical framing option for many buildings, and are often the most economical option for those having a steeply sloped roof. Some advantages of CFS trusses are that they have an excellent span-to-weight ratio, can be shop-fabricated into custom shapes, and are non-combustible. …
Imagine yourself inside a house that rests on a frozen, frictionless lake when a violent earthquake occurs. Apart from noticing some up-and-down vibration, how would you know the ground is shaking? The lack of a horizontal “connection” to the earth would allow the ice to shift horizontally without affecting the house. …
Two major earthquakes hit the Cephalonia Island of Greece on January 26th and February 3rd of 2014, with magnitudes of M = 6.0 and 6.1. For comparison, the recent South Napa earthquake of August 24, 2014 had M = 6.0 (EERI, 2014) and the Northridge earthquake of 1994, which has been used in development of seismic codes, had M = 6.7 (NCEER, 1994). …
Life safety has always been a fundamental goal of U.S. building codes. With the introduction of the International Building Codes (IBC) in 2000, new demands have been placed on engineers, manufacturers and builders who produce structures in earthquake-prone regions. Prior to the IBC, engineers were accustomed to designing buildings to prevent damage such as buckling and yielding. …
Balancing blast load design and research with project requirements can be challenging. A simple renovation, like one including window replacement, may seem straightforward especially when seismic rehabilitation is not a concern, but on a West Coast US Military Base it is anything but. Accurately incorporating blast research with what is known about the construction of an existing building is the focus of this article. …
As early as 1970, the structural engineering and building safety community recognized that a large number of two-, three- and four-story woodframe buildings, designed with the first floor used either for parking or commercial space, were built with readily identifiable structural deficiencies, referred to as a “soft story”. Often these buildings also have a strength deficiency when compared to the stories above, in which case they are also classified as “weak”. …
Advances in computational tools for earthquake engineering analysis continue to broaden the structural engineer’s ability to conduct performance-based simulations, evaluate ductility, and make decisions on performance criteria that involve deformations of a structure beyond the elastic limit. …
In the past few years, building for natural disasters – already a consideration for structural engineers – has been thrust into the public eye after recent tornados wiped out entire cities and took many American lives. Moore, Okla., Joplin, Mo., and Tuscaloosa, Ala. are all recent examples of areas that have experienced the greatest losses, both in infrastructure and human life. Engineers in the construction industry work to stay aware of these challenges when setting out to build safe, strong and durable buildings for tenants and occupants. …
After fire exposure, design professionals are sometimes called upon to determine if the charred heavy timbers (Figure 1) are safe for future use without additional support or repairs. In this article, the authors present a sequence of reasoned steps that will help design professionals analyze charred timbers and gain the type of information needed to decide whether the charred timbers are adequate based on the applicable building code. …