Civil Engineering Reference
In-Depth Information
currently in existence. In its final form, this code will be mandatory throughout the EEC
and eventually replace all existing national documents.
Distinction is made in the document between 'Principles' (denoted by the letter P),
comprising general statements, definitions, requirements and analytical models for which
there is no alternative, and 'Application Rules' for which it is permissible to use
alternatives provided they accord with the relevant Principles.
This is a lengthy document with comprehensive methods of static and dynamic design
for wind loads. No basic wind speeds are provided in the standard—these are to be
provided separately in each National Annex. The basic wind velocity is a 10-min mean
velocity at 10 m height in open country terrain, with an annual probability of exceedence
of 0.02 (50-year return period).
15.2.3
ASCE Standard ASCE 7-05. Minimum design loads for
buildings and other structures
ASCE/SEI 7-05 is a complete loading standard covering all types of loads, and the wind
loading part (Section 6 and its associated Commentary) is a relatively small component
of the whole document.
From 1995 onwards, ASCE-7 has incorporated a number of significant changes in the
wind load provisions from the 1993 and earlier editions. This includes the use of a 3-s
gust wind speed instead of the 'fastest-mile-of wind' as used in the past, a new zoning
system for basic wind speeds, the incorporation of topographic factors, some new data on
pressure coefficients, a simplified procedure for buildings less than 9 m in height and a
revised method for along-wind dynamic response calculation.
The ASCE Standard has no legal standing of its own, but its provisions are cited by
many of the regional, city and county building codes. The three major regional building
codes in the United States have merged to form a single 'International Building Code'.
This draws on the ASCE Standard for wind load provisions.
15.2.4
AIJ Recommendations for loads on buildings
The Recommendations of the Architectural Institute of Japan (AIJ) were revised in 2004
and are a comprehensive loading code including the effects of dead, live, snow, seismic,
temperature, earth and hydraulic pressure, as well as wind loads. Chapter 6 on wind loads
comprises 54 pages, with 114 pages of Commentary. The derivation of the wind loading
section of the 2004 edition of the AIJ, and revisions from the 1993 version, were
described in detail by Tamura
et al.
(2004).
Like the ASCE Standard, this is a comprehensive and advanced wind loading
document, although the Recommendations have no legally binding standing in Japan.
The Building Law of Japan has a separate set of wind loading rules—BSLJ-2000
(Ministry of Land, Infrastructure and Transport, 2000). As the latter does not have a
comprehensive set of rules for cross-wind and torsional dynamic response, the AIJ is
commonly used by structural designers for buildings greater than 60 m in height.
