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[SEAOC] LA City Earthquake Hazard Reduction Ordinances

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Three new ordinances have just been adopted by the City of Los
Angeles which may be of interest to SEAOC list subscribers.  Each of
these ordinances is intended to reduce earthquake hazards for certain
types of buildings in LA City by encouraging voluntary compliance to
minimum standards for certain structural systems.

Ord. # 171258 adds Division 94 to the LA building code, entitled
VOLUNTARY EARTHQUAKE HAZARD REDUCTION IN EXISTING
HILLSIDE BUILDINGS.    It provides voluntary retrofit standards under
which existing hillside buildings shall be permitted to be structurally
analyzed and retrofitted.  It applies to buildings which were designed
under building codes prior to 6/19/95 and constructed on or into slopes
in excess of three horizontal to one vertical.

Ord. #171259 adds Division 92 to the LA building code, entitled
VOLUNTARY EARTHQUAKE HAZARD REDUCTION IN EXISTING WOOD
FRAME RESIDENTIAL BUILDINGS WITH WEAK CRIPPLE WALLS AND
UNBOLTED SILL PLATES.  It sets proscriptive standards for
strengthening underfloor enclosures.  This ordinance also provides a
design standard for the use of alternate materials or an alternate method
of construction in lieu of the proscriptive standards, provided the
alternate materials and methods are prepared by an architect or
engineer.  It applies to light wood frame Group R, Division 3 and Division
1 occupancies with no more than four dwelling units when they contain
one or more of the structural weaknesses described in the ordinance.

Ord #171260 adds a new Division 95 to the LA building code, entitled
VOLUNTARY EARTHQUAKE HAZARD REDUCTION IN EXISTING
REINFORCED CONCRETE BUILDINGS AND CONCRETE FRAME
BUILDINGS WITH MASONRY INFILLS.  The provisions of this ordinance
may be applied to all buildings in LA City which were designed under
building codes in effect prior to January 13, 1976, or built with building
permits issued prior to 1/13/77, having concrete floors and/or concrete
roofs supported by reinforced concrete walls or concrete frames and
columns, and/or concrete frames with masonry infills.

Each of these ordinances was developed as voluntary earthquake
reduction retrofit standards to reduce the damage and loss of life to the
infrastructure within Los Angeles City and to encourage individual
owners to strengthen their existing buildings against seismic forces,
where both of the current California Building Code and the Uniform
Building Code do not have such standards.  These ordinances are
intended to provide a minimum life-safety performance level and
cost-effective design for particular classes of buildings.  Prior to their
enactment, the LA City codes did not have a method to strengthen
existing older buildings to resist earthquakes, except for the mandatory
provisions of Division 88 (pre-1934 Unreinforced Masonry Buildings)
and Division 91 (pre-1976 Concrete Tilt-up Buildings).

Each of these ordinances was approved on 8/27/96.  Copies of each
ordinance may be purchased from the Los Angeles City Clerk for $1.00
per document plus $0.10 per page.  The City Clerk will accept telephone
requests for single copies of the ordinance(s), and will then mail a copy
with an invoice for payment.  Their telephone number is (213) 485-5705.
 The City Clerk's office hours are 8:00 am - 5:00 pm M-F.  Copies may
also be obtained by visiting the City Clerk's public counter in Los
Angeles City Hall, 200 N. Spring St, Room 395, Los Angeles, Ca. 90012.

David Schnitger


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