CUBiC Code - Seismic
CUBiC Code - Seismic
CUBiC Code - Seismic
YEAR: 1985
SPECIFIC ITEMS:
1. GENERAL PHILOSOPHY
Scope of Code is for new Buildings and does not cover requirements for
Design and Construction of special structures including, but not limited to,
bridges, transmission towers, industrial towers and equipment,piers,
wharves, hydraulic structures, off-shore structures and nuclear reactors
These special structures require special consideration of their response
characteristics and environment which is beyond the scope of the CUBiC
provisions..
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DUCTILITY- The building as a whole, and all of its elements that resist
seismic forces or moments, or that in case of failure are a risk to life, shall
be designed to possess ductility.
TERRITORY Z VALUE
JAMAICA .75
ANTIGUA .75
ST.KITTS-NEVIS .75
MONTSERRAT .75
DOMINICA .75
ST.LUCIA .75
ST.VINCENT .50
GRENADA .50
BARBADOS .375
NW TRINIDAD .75
REST OF TRINIDAD .50
TOBAGO .50
GUYANA ESSEQUIBO .25
REST OF GUYANA .00
BELIZE –AREAS WITHIN
100KM OF SOUTHERN
BORDER I.E. INCLUDING
SAN ANTONIO AND
PUNTA GORDA BUT
EXCLUDING MIDDLESEX,
POMONA AND STANN
CRECIL .75
- REST OF BELIZE .50
Not considered.
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2.4 Site Requirements
Nine Structural Types for Steel and Concrete and Three for Timber.
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Frame Type (Ductile steel, concrete, timber).
Dual Type (Frame + Wall combination. Frame with 25% of shear
demand; steel, concrete, masonry, timber)
Wall Type (either concrete, masonry or plywood walls or steel or timber
braced frames)
Cantilever Type (or Inverted Pendulum)
Others Type (none of the above)
Not considered
4. SEISMIC ACTIONS
Not considered.
Not considered.
Not considered.
Not considered.
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5. DESIGN FORCES, METHODS OF ANALYSIS AND DRIFT LIMITATIONS
[2.305, 2.305.17, 2.306]
“Lateral deflections or drift of a storey relative to its adjacent stories shall not
exceed 0.005 tiimes the storey height unless it can be demonstrated that
greater drift can be tolerated. The displacement calculated from the
application of the required lateral forces shall be multiplied by 1.0/K to obtain
the drift. The ration 1.0/K shall not be less than 1.0.”
None given.
V = ZCIKS W
where
V = Total Lateral Force or Shear at the base
Z = Seismic Zonal Coefficient (see 2.1)
C = 1/15√T
C need not exceed 0.12
For moment resisting structures where the frames are not enclosed or adjoined
by more rigid components tending to prevent the frames from deflecting when
subjected to seismic forces:
T= CThn3/4
Where
CT= 0.035 for steel frames
CT= 0.025 for concrete frames
hn= the height in feet above the base to the highest level of the
building
T= 0.05hn/√L
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Where
L = the overall length (in feet) of the building at the base in the
direction under consideration.
W= Total Weight (100% of Permanent (Dead) Load + applicable
portions of other loads.
Fi = V [ wi hik / Σ Wk hkk ]
Required whenever Static Method Procedures (see 5.3) are not allowed.
Combination of modes according to SRSS .
All structures with Plan Structural Irregularities (see 3.3) where the
vertical resisting elements depend on diaphragm for shear distribution at any
level, the shear resisting elements shall be capable of resisting a torsional
moment assumed to be equivalent to the storey shear acting at an eccentricity of
not less than five percent of the maximum dimension at that level..
See ( 5.1)
Not considered
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6. SAFETY VERIFICATIONS
Not considered
Not considered
Not considered
Not considered
Not considered
Not considered in CUBiC but the draft Small Building Code of Trinidad and
Tobago (SBCTT) has a number of sections which deal with Lateral Load
Design for earthquakes in Sections 3.1.7 and 3.2.6 on pages 16 to 21 and 42
to45. These pages can be viewed at URL: http://www.boett.org
In the preparation of this SBCTT, extensive use has been made of the
Caribbean Uniform Building Code (CUBiC). It was noted that at this time
CUBiC is being considered for revision and the management committee for
the revision project has elected to make use of the International Code Council
Inc. of the USA in the provision of the base documentation for this review. In
like manner for this code use has been made of the ICC year 2000
International Residential Code Final Draft 1998.
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The exercise was managed by the Board of Engineering of Trinidad and
Tobago sponsored by the Joint Consultative Council of the Construction
Industry (T&T) and the Interim National Physical Planning Commission (T&T)
with support of the Trinidad and Tobago Bureau of Standards (TTBS).
Not considered