Manufactured Homes - Probability of Failure and the Need for Better Windstorm Protection Through Improved Anchoring Systems.
Manufactured Homes - Probability of Failure and the Need
for Better Windstorm Protection Through Improved
Anchoring Systems.
(2237 K)
Marshall, R. D.
NISTIR 5370; 54 p. November 1994.
Available from:
National Technical Information Service
Order number: PB95-143129
Keywords:
building technology; codes; standards; hurricanes;
manufactured housing; mobile homes; natural disasters;
soil anchors; structural engineering; wind damage; wind
engineering; wind loads; windstorm protection
Abstract:
Probabilities of failure are estimated for structures
designed in accordance with the wind load provisions of
the Manufactured Home Construction and Safety Standards
(MHCSS) that were in effect at the time of Hurricane
Andrew (1992) and for structures designed in accordance
with the wind load provisions of ASCE 7-88 (Minimum
Design Loads for Buildings and Other Structures). It is
concluded that for a 10-yr exposure the probability of
structural failure in a hurricane-prone area such as
Dade County, Florida, using the MHCSS wind load criteria
is approximately 10 times that determined using the wind
load requirements of ASCE 7-88. This same ratio holds
for an extra-tropical wind climate such as that of
Omaha, Nebraska. For Tucson, Arizona, this ratio is
approximately 5. Test data for various components of
traditional manufactured home anchoring systems are
examined and it is concluded that the load capacity of
these systems is substantially less than the load
capacities implied by the MHCSS and by current standards
covering the installation of manufactured homes. It is
recommended that traditional anchoring systems that
utilize allow soil anchors be designed on the basis of
factored loads and that preloading be made an integral
part of the installation process. A new approach to
providing windstorm protection for manufactured homes
located in hurricane-prone regions needs to be
developed.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899