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Design of Residential Buildings in (High Wind)
Coastal Areas
Jeffrey Havelin, P.E.
Overview
This course will review the
design process required for residential buildings (one to three-story) to
withstand hurricanes and other severe natural hazard events.
The required calculations for
all of the site specific design loads (forces) which will be applied to the
structure is not within the scope of this course, however these site specific
forces, which have been previously calculated in a case study, will be used in
this course to design a structure that can withstand these forces.
To determine these
site-specific design loads it is suggested that the design professional should
refer to pertinent sections of the IRC 2000, in addition to those sections of
the IBC 2000 which may be cited within this course. Additional reference sources
should also include one or more of the following sources in high wind zones.
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Minimum Design Loads for Buildings and other structures (ASCE
7-98)
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American Forest and Paper Association (AF&PA) Wood Frame Construction Manual
for One and Two- Family Dwellings (WFCM)
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Southern Building Code Congress International Standard for Hurricane Resistant
Residential Construction (SSTD 10)
In
this course the design method is Allowable Stress Design (ASD), so there are
factors of safety (FS) built into the development of the material stresses and
the forces at the connections. This design method has been chosen because (ASD)
continues to be the predominant design method in light-frame, residential, wood
construction.
The
design process involves the following steps after determining
all of the site-specific
design loads (forces):
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Determining the building’s foundation, structural frame, and envelope
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Determining the connections between individual elements
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Determining the elevation, placement, and support for utilities
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Selecting the appropriate materials
The
course concentrates on determining the actual forces at connections and stresses
on specific components, which are applied through vertical and horizontal load
paths. The entire design process is based on the fundamental premise that
anticipated service and natural hazard loads can and must be transferred through
the building in a continuous path to the supporting soils.
Any
weakness in that continuous path is a potential point of failure of the
building, and any failure creates the possibility for large property losses and
the potential for loss of life.
The
student must take a multiple-choice quiz consisting of sixty (60) questions at the end of this course
to earn PDH credits.
Specific Knowledge or Skill Attained
This course teaches the
following specific knowledge and skills:
Design of structures which are capable to withstand the forces from various
types of loadings which could be subjected to a one- to three-story residential
buildings during hurricanes or other severe natural hazard events.
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Dead loads
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Live loads
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Flood loads
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Wind loads
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Earthquake (seismic)
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Snow loads
Prevention of Primary and Secondary Failure Modes
Uplift:
Vertical forces caused by wind or buoyancy exceed the weight of the
structure and the strength of the soil anchorage. The building fails by being
lifted
off its foundation or because the foundation pulls out of the soil.
Overturning:
The
applied moments caused by wind, wave, earthquake, and
buoyancy forces exceed the resisting moments of the building’s weight and
anchorage. The building fails by rotating off its foundation or because the
foundation rotates out of the soil.
Sliding or Shearing:
Horizontal forces exceed the friction force or strength
of the
foundation. The building fails by sliding off its foundation, by shear
failure of components transferring loads to its foundation, or by the
foundation sliding.
Collapse:
Collapse is a secondary mode of failure. Structural components fail
or
become out of plumb or level under uplift, overturning, or sliding. The
building then becomes unstable and collapses.
Buildings under extremely heavy vertical downward loads, such as snow, can
also
fail in bending, shear, or compression of primary structural members. For
purposes of this manual, it is assumed the designer is familiar with the design
concepts used to support these ordinary gravity loads.
The Building
Design process will be based on the following steps
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Use
codes, standards, experience, judgment; state givens and assumptions.
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Apply loads to building starting at the top; assume a building type, frame,
and materials; assume a design approach (ASD, strength).
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Determine forces at
connections and stresses on components; apply through vertical and
horizontal load paths
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Specify connectors or connection methods to satisfy load conditions; specify
materials that meet stress levels.
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Note
design assumptions on drawings; specify design details on drawings
Fact:
The National Flood Insurance
Program (NFIP) regulations state that for buildings in V zones, “a registered
professional engineer or architect shall develop or review the structural
design, specifications and plans for the construction, and shall certify that
the design and methods of construction to be used are in accordance with
accepted standards of practice” for meeting the provisions of the NFIP
regulations regarding buildings in V zones.
Course
Click on the
following PDF attachment and review Chapter 12, "
DESIGNING THE BUILDING" from the third edition of "Coastal
Construction Manual" -Publication (FEMA-55) prior to taking a quiz for credit.
You will be quizzed on the attached document in its entirety.
Design of Residential Buildings in High Wind Coastal Areas (3.3 MB)
Various formulas and
calculations for the site-specific loadings, which are used in this course, can
be reviewed in Chapter 11 of this document. The course text sometimes also
references sections located within other chapters of the complete FEMA document.
Although this additional
information is not required to complete the quiz, a link is provided below with
information on how to contact FEMA to obtain a full copy of the document for
reference.
http://www.fema.gov/pdf/plan/prevent/nhp/nhp_fema55.pdf
Having Trouble Downloading the PDF File?
Right click on the link. Select "Save Target As..."
Then save on your desktop. To view the file, double click the icon on your
desktop and return to this page to take the quiz.
You may need Acrobat Reader to view this document.
Click on the link below to download a free copy of Acrobat Reader.
To obtain PDH credits for this course, you will need to take a quiz for
credit. Click on the link below.
(To take the quiz,
your web browser must be set to accept cookies. See how to
check your cookie settings.)
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