ANSI/AISC 341-05 Seismic Provisions for Structural Steel Buildings Including Supplement No. 1

The Seismic Provisions for Structural Steel Buildings, hereinafter referred to as these Provisions, shall govern the design, fabrication and erection of structural steel members and connections in the seismic load resisting systems (SLRS) and splices in columns that are not part of the SLRS, in buildings and other structures, where other structures are defined as those structures designed, fabricated and erected in a manner similar to buildings, with building-like vertical and lateral load-resisting-elements. These Provisions shall apply when the seismic response modification coefficient, R, (as specified in the applicable building code) is taken greater than 3, regardless of the seismic design category. When the seismic response modification coefficient, R, is taken as 3 or less, the structure is not required to satisfy these Provisions, unless specifically required by the applicable building code. These Provisions shall be applied in conjunc tion with the AISC Specification for Structural Steel Buildings, hereinafter referred to as the Specification. Members and connections of the SLRS shall satisfy the requirements of the applicable building code, the Specification, and these Provisions. Wherever these provisions refer to the applicable building code and there is no local building code, the loads, load combinations, system limitations and general design requirements shall be those in SEI/ASCE 7.
User Note: The applicable building code generally restricts buildings designed with an R factor of 3 or less to seismic design categories (SDC) A, B or C; however, some systems such as cantilever columns that have R factors less than 3 are permitted in SDC D and above and these Provisions apply. See the applicable building code for specific system limitations. Part I includes a Glossary that is specifically applicable to this Part, and Appendices P, Q, R, S, T, W and X.

The DESIGN GUIDE for the FIRE PROTECTION of BUILDINGS

The Design Guide is applicable to:
• All new buildings, excluding dwelling houses, maisonettes and flats for which the provisions of the supporting documents to Building Regulations are considered to provide adequate property protection;
• Major extensions and the refurbishment and upgrading of existing buildings within the occupancy types covered. The recommendations of the Design Guide dealing with compartmentation (Part 3) recognise that institutional and other residential buildings, including hotels, typically do not contain large undivided compartments. In the United Kingdom the design and construction of new buildings and alterations to existing buildings are controlled by the following legislation of which the prime objective is life safety:
England and Wales: The Building Regulations;
Scotland: The Building Standards (Scotland) Regulations;
Northern Ireland: The Building Regulations (Northern Ireland).
The Design Guide for the Fire Protection of Buildings should be used by the building designer in conjunction with the documents supporting the appropriate regulations cited above. This Design Guide adopts many of the structural fire resistance levels given
in Approved Document B to the Building Regulations and provides guidance to enable these to be achieved. However, it is essential to recognise that that the approach of building regulations will often be inadequate to satisfy property and business protection objectives and the increased risk management standards required. Approved Document B states that ‘The protection of property, including the building itself, may require additional measures, and insurers will in general seek their own higher standards . . .’ Such additional measures, including increased levels of fire resistance are designed to ensure, amongst other things, that as far as possible the fire can be restricted to the compartment of origin throughout its duration. This is fundamentally different to building regulations, which are concerned with life safety and, where as a result, compartmentation may be inadequate to prevent major damage after escape from the building has been satisfactorily accomplished. This is particularly true for many large single-storey, industrial buildings in respect of which the building regulations have very little influence, and where means of escape requirements can often be satisfied without resort to any form of compartmentation. The Design Guide replaced the LPC Code of Practice for the Construction of Buildings in November 1996, which was then withdrawn. Regular updating of the Design Guide is undertaken as required

Fire rated non-loadbearing partitions

Lightweight non-loadbearing partitions are used in all types of buildings; the actual form of construction will be determined by the specified performance criteria and desired appearance. Fixed stud and sheet or panel partitions are normally used in housing, schools and industrial buildings, whereas re-locatable frame and sheet systems are more appropriate for offices and other commercial buildings. Twin-framed constructions of various types are also available, which are used to sub-divide multi-screen cinema complexes and other applications requiring high sound insulation. To some extent all partitions help to contain the effects of fire and depending on the size and function of a building, national Building Regulations require lightweight non-loadbearing partitions to have specific fire resistance. When correctly specified and installed, the partitions will contribute substantially to the safety of the occupants of the building. Insurance companies may also specify particular requirements for certain applications such as property protection. Accordingly, many partition suppliers carry out extensive research and development and are able to demonstrate that their partition designs can achieve satisfactory levels of fire resistance when tested in the laboratory to the appropriate standards. Details of such fire rated partition designs, which cover a range of requirements, are described in this publication for fire resistance periods ranging from 30 minutes to 240 minutes (or more).
This publication relates to the fire resistance performance of partitions, which can be considered as a single element in their own right, with no interruptions in their function from such items as doors or glazing. This is the vitally important starting point for designing partitions that will achieve suitable fire resistance between spaces. It should be appreciated that the fire resistance of a partition assembly containing other components, such as a door or glazing, is likely to be controlled by the performance of the weakest component, In addition to the fire resistance of partitions, based upon their behaviour when subjected to a standard fire resistance test, this publication also covers reaction to fire (a property of individual materials rather than the complete element). Reaction to fire may also need to be considered separately in order to meet the requirements of Building Regulations. The classification of materials can be obtained from the partition manufacturer/supplier, but test evidence (test(s)) and/or assessment(s) must support the claimed fire performance. References to the following types of partition are not included in this publication, as these will be dealt with in later issues.
Fully glazed partitions
Tracked, sliding or folding partitions
Shaftwalls and stairwalls
Cavity Barriers
Screens (free-standing partitions)
Partitions made up from different forms of construction