Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 1
Architectureand the Safety and Vulnerability of Buildings
in Earthquake Zonesq
Chairman – Tony Gibbs
Panellists:Robert Woodstock, Gary Turton, Jenifer Smith
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 2
Buildings are designed by architects and engineers. In reality, in most cases, buildings principally for human y, , g p p yoccupancy are designed conceptually by architects. That is to say that architects are the ones principally responsible for the configuration of buildings for human occupancy.
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 3
C ldC Arnold
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 4
Configuration has to do with the shape and size of the b ildi I it bl h d i t l t tbuilding. Inevitably shape and size to a large extent determines (or greatly influences) the type, shape, arrangement size location and most other aspects ofarrangement, size, location and most other aspects of the structural concept.
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 5
C Arnold
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 6
In the words of Geoffrey Wood (one of the five f di t f O A & P t )founding partners of Ove Arup & Partners):
“Earthquake‐resistant design is really a problem forEarthquake resistant design is really a problem for architects."
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 7
Either the architect has a better‐than‐usual knowledge of the basic principles of the conceptual design of earthquake resisting systems
or
The architect should involve the structural engineer in the initial discussions and development of the building concept.
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 8
Tony Gibbs
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 9
The Tri‐services Manual of the USA Army, Navy and Air Force states:Force states:
"A great deal of a building's inherent resistance g f gto lateral forces is determined by its basic plan layout. . . .
"Engineers are learning that a building's shape, symmetry and its general layout developed in the conceptual stage are more important than the accurateconceptual stage are more important than the accurate determination of the code‐prescribed forces. . . ."
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 10
Irregularities in the floor planIrregularities in the floor planIrregularities in the floor plan
10
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 11
Structural engineer William Holmes, writing in 1976, states:
"It has long been acknowledged that the configuration and the simplicity and directness of theconfiguration, and the simplicity and directness of the seismic resistance system of a structure, is just as important as the actual lateral design forces."
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 12
Examples of structures withirregularities in elevation
Examples of structures withirregularities in elevation
Examples of structureswith irregularities in elevation
12
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 13
Discontinuity in the elementsand the flow of forcesDiscontinuity in the elementsand the flow of forces
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 14
Henry Degenkolb is emphatic in stressing the importance of configuration:
"If we have a poor configuration to start with, all th i d i t i b i llthe engineer can do is to improve a basically poor solution as best he can. Conversely, if we start off with a good configuration and a reasonable framinga good configuration and a reasonable framing scheme, even a poor engineer can't harm its ultimate performance too much.
"This last statement is only slightly exaggerated.”
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 15
Those quotations above warrant discussion among the various disciplines involved in the design and building processes. Terán (Nicaraguan architect) recommends th t b ildi b " i l ti t i lthat buildings be "simple, continuous, symmetrical, straightforward, and repetitive". This advice is given not as an absolute but as a qualitative factor thatnot as an absolute, but as a qualitative factor that influences the reliability of the structure. Terán asks for understanding and knowledge among the disciplines, not the imposition of mandatory constraints.
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 16
Use of seismic joints for structural designs of buildings with complex floor plans
Use of seismic joints for structural designs of buildings with complex floor plans
Use of seismic joints for structural designs of buildings with complex floor plans
16
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 17
Asymmetry (false symmetry) due to the location of structural elements
Asymmetry (false symmetry) due to the location of structural elements
Asymmetry (false symmetry)due to the location of rigid elements
17
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 18
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 19
Irregular elevationsIrregular elevationsIrregularities in elevation
19
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 20
Soft storiesSoft stories
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 21
Damage caused by shearing forceon ground-floor columnsDamage caused by shearing forceon ground-floor columns
PAHO
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 22
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 23
Structural damage mechanismsStructural damage mechanismsStructural damage mechanisms
23
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 24
Interaction between structural and nonstructural elements
Interaction between structural and nonstructural elements
Interaction betweenstructural and nonstructural elements
24
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 25
Nonstructural ComponentsNonstructural ComponentsNonstructural Components
25
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 26
Response of different components and contents of a building during an earthquake
Response of different components and contents of a building during an earthquake
Response of different components and contents of a building during an earthquake
T. Guevara, 1999
26
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 27
Architectural componentsthat run across
Architectural componentsthat run across
SeismicJointSeismicJoint
that run across seismic joints must be
that run across seismic joints must bemust becorrectly detailedmust becorrectly detailed
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 28
Basic servicesmay be interrupted d t f il
Basic servicesmay be interrupted d t f ildue to failures associated with the inappropriate crossing
due to failures associated with the inappropriate crossinginappropriate crossing of seismic jointsinappropriate crossing of seismic joints
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 29
Performance Basis1997 BSSC NEHRP Provisions
Building P f
Frequent
Performance
Frequent
Motion Ordinary Buildings
Emergency Response
Design
roun
d M High Occupancy
Maximum Considered
Gr
FEMA
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 30
EdificioConvenzionale
Edificio conIsolamento alla base
Fc2 >> Fc1
Ac >> AiFc >> FiDc >> DiSc >> Si Fi2 Fi1
BRITE EURAM Project, 1993Base isolated building
Conventional building
Ac Ai
Fc2Fi2
ndro
Mar
telli
ndro
Mar
telli
Dc DiFc1 Fi1
urce
: Ale
ssan
urce
: Ale
ssan
SiScSo
uSo
u
A Z I O N E S I S M I C A
H i t lH i t lHorizontal seismic action
HorizontalHorizontalseismic isolationseismic isolationseismic isolationseismic isolation(case of High Damping Rubber Bearings (case of High Damping Rubber Bearings –– HDRB)HDRB)
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 31
Base-isolation technique
with
with C
entehout B
h Base
er of Informat
Base-is
e-isola
ion on Naturasolatio
ation
l Disaster R
eseon earch
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 32
EdificioConvenzionale
Edificio condissipatori Energetici
Fc2 >> Fc1
Ac > AeFc > FeDc > DeSc > Se Fe2 > Fe1
EEAc AeFc2 Fe2
EnergyEnergydissipationdissipation
Dc DeFc1 Fe1
dissipationdissipation
Sc Se Tests with electroinductive dampers on the ENEA shake table.
A Z I O N E S I S M I C A
Source: Alessandro MartelliSource: Alessandro Martelli
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 33
Elastic-plastic d
SMAload
limiting dampers
gdevices
Visco elastic
Viscous dampers
Visco-elastic dampers
Shock transmitterSource: Alessandro MartelliSource: Alessandro Martelli
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 34
Method of “strengthening”:dissipation of energy used in the central offices of
Instituto Mexicano del Seguro Social-México (PAHO)Instituto Mexicano del Seguro Social-México (PAHO)
Architectural Considerations(GEM launch in the Caribbean)
04 May 2011
Tony Gibbs 35
The panel will examine the problems for theThe panel will examine the problems for the architectural designer when confronted by the earthquake hazard and some of the possible solutions q pto those problems.
It is also hoped that the GEM regional programme would have a measurably positive influence on reducing the vulnerability of future buildingsreducing the vulnerability of future buildings.