An important objective of building codes and regulations is to provide a fire-resistive built environment. Thus, building fire safety regulations contain numerous provisions including directives for the minimum number of exits, the maximum travel distances to exits, minimum exit widths, fire compartment requirements, fire detection and suppression mandates, and the protection of structural members in buildings. The focus of this design guide is the fire protection of structural steel framing systems. The guide is arranged such that important information for fire protection design, including that for building codes and test standards, is repeated within the design chapters to allow them to function as self-containing, stand-alone sections.
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Categories: Engineering Code
Steel-framed parking structures are increasing in popularity. The recent trend toward steel has prompted industry analyst Dale Denda of the Parking Market Research Company to comment that “exposed steel-frame construction is back as a recognized option for multi-story parking structures.” (Parking Today, June 2001)
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Categories: Engineering Code
There are two principal types of fasteners used in contemporary fabricated steel structures—bolts and welds. Both are widely used, and sometimes both fastening types are used in the same connection. For many connections, it is common to use welds in the shop portion of the fabrication process and to use bolts in the field. Welding requires a significant amount of equipment, uses skilled operators, and its inspection is a relatively sophisticated procedure. On the other hand, bolts are a manufactured item, they are installed using simple equipment, and installation and inspection can be done by persons with only a relatively small amount of training.
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Categories: Engineering Code
AISC and other specifications for the design of structural steel usually refer to standards published by the American Society for Testing and Materials (ASTM). Table 1.1a presents a historical summary of the pertinent ASTM standards for structural steels for buildings over the last century, with the relevant yield points and tensile strengths specified.
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Categories: Engineering Code
The staggered-truss framing system, originally developed at MIT in the 1960s, has been used as the major structural system for certain buildings for some time. This system is efficient for mid-rise apartments, hotels, motels, dormitories, hospitals, and other structures for which a low floor-to-floor height is desirable. The arrangement of story-high trusses in a vertically staggered pattern at alternate column lines can be used to provide large column-free areas for room layouts as illustrated in Fig. 1.1. The staggered-truss framing system is one of the only framing system that can be used to allow column-free areas on the order of 60 ft by 70 ft. Furthermore, this system is normally economical, simple to fabricate and erect, and as a result, often cheaper than other framing systems.
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Categories: Engineering Code
The January 17, 1994 Northridge Earthquake caused brittle fractures in the beam-to-column connections of certain welded steel moment frame (WSMF) structures (Youssef et al. 1995). No members or buildings collapsed as a result of the connection failures and no lives were lost. Nevertheless, the occurrence of these connection fractures has resulted in changes to the design and construction of steel moment frames. Existing structures incorporating pre-Northridge1 practices may warrant re-evaluation in light of the fractures referenced above. The work described herein addresses possible design modifications to the WSMF connections utilized in pre- Northridge structures to enhance seismic performance.
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Categories: Engineering Code
