Optimization of Seismic Resistance in Buildings

This assignment delves into the optimization of seismic resistance in buildings, covering various techniques such as horizontal bands, vertical reinforcements, and architectural design principles. It also discusses morphological solutions to prevent pseudo-resonance, seismic torsion, building collision, and concentrated weight effects. The assignment provides a comprehensive overview of seismic design principles and architectural solutions for earthquake-resistant construction.

OPTIMIZATION OF SPECIFIC
ELEMENTS WITHIN EARTHQUAKE
RESISTANT CONSTRUCTION

HORIZONTAL BANDS
 Horizontal band refers to a technique of
reinforcing masonry buildings using bands of
higher tensile strength. This is done to form
an altogether connection thereby
establishing a single unit.
 Horizontal bands are located at various levels
including lintels, plinth levels of a building
and ceiling levels.
 Horizontal bands are classified as Plinth,
Lintel, Gable and Roof Bands

 The Plinth Band is mostly useful in regions
with weak soils especially in the hilly areas
where the soil is soft and has uneven
properties (Manohar, 2015, p.258).
 Lintel Bands are provided at the lintel level.
The band experiences bending during
earthquakes therefore call for special
supervision and care during construction

 Roof Bland is mainly used with buildings
whose roofs are made of flat timber. The
band is not usable for roofs made of bricks or
concrete slabs since reinforced concentrate
slabs are themselves horizontal bands
(Manohar, 2015, p.312).
 Gable Bands are used in sloping roofs i.e.
roofs with truss construction.
Design Details for Horizontal Bands

A roof diaphragm is a
component of the
structure of a braced
frame building that
assist in the
distribution of loads
across the load bearing
members thereby
leading to an
equalization of the
pressure and making
the frame rigid.

 The seismic resistance capacity of buildings is often
reduced when the architectural designs and structural
designs interact.
 Several studies have been done to ensure such situations
are avoided.
 Various theories have been developed to give architects
an opportunity to come up with a systematic study and a
methodology that is applicable to the architectural
designs of buildings that are located in seismic zones.
 One of such theories is called Earthquake Resistance
Architecture.
 Through this theory, situations that can affect the
earthquake resistance behavior negatively are avoided.
 In this theory, a building is perceived as a set of
components that that interact when an earthquake
occurs.

ARCHITECTURE IN SEISMIC ZONES
• Refers to the
responsibilities of an
architect aimed at
solving problems
related with seismic
waves in highly
hazardous seismic
zones.
• Among the study lines
covered in architecture
in seismic zones
include:
 Urban planning
 Emergency
 Seismoresistant
Building Architecture
 Preservation and
Restoration of Patrimony of
Historical Buildings
 Esthetical and
Morphological
Characteristics of Seismic
Resistant Architecture

Vertical Reinforcements
 Vertical reinforcements are
embedded in wall piers to force the
slender masonry piers to
experience bending as opposed to
rocking.
 In the case of wider piers, the
vertical members are used to
increase their capacity to resist
horizontal earthquakes as well as
delay in X-cracking (Altenbach,
2013, p.112).
 With adequate cross sectional area,
the vertical bars aids in preventing
the bars from experiencing tension.
 Vertical bars also protect walls from
sliding and collapsing in the
direction of the line of weakness.

Protection of wood and bamboo poles
 Wood and bamboo poles can be protected by:
 Avoiding direct contact with the soil so as to
prevent rotting. In case where they are to be
buried in the soil, painting with special
bitumen paint or tar is recommended
(Altenbach, 2013, p.169).
 Handling with care as bamboo may crack
when it hits the ground
 Avoid using nails to join the poles
Protection of steel bars
 Applications of coating: The various coatings
include stainless steel cladding, hot dip
galvanizing and epoxy coating that is fusion
bonded
 A plinth beam is cement beam laid
horizontally across the house periphery on
top of the foundation. It serves to provide
support to the walls, prevent leakage of water
into the foundation as well as hold the house
together.

SEISMORESISTANT ARCHITECTURE
• Seismoresistant
Architecture gives
focus to the
interaction of each of
the building’s
subsystems during
seismic shaking in
such a way that the
architectural project
does not in any way
come from structural
maladjustments that
would lower the
seismoresistant
capacity of the
building.

• The objectives of Seismoresistant Architecture include:
 Prevention of seismoresistant stepping
 Optimization of seismoresistance (Cruz, 2015,
p.123)
• Four study lines were followed during the development
of Seismoresistant Architecture. Among them include:
 Definition of the general principles of
Seismoresistant Building Architecture
 Development of a Seismoresistant Architecture
dependent on the congruent interrelations between
each of the interacting structural systems of a
subsystem
 Improvement of the Seismoresistant Structural
Design within the provisions of Architectural Design
(Steinbuch, 2015, p.177)
 Schematization of the compatibility and interactions
between Seismoresistant Architectural Design and
Structural Design

• The basic principle
operation of
Seismoresistant
Architecture is that
“The
seismoresistant
structural elements
should produce the
stiffness, strength,
ductility and
synchronization as
anticipated in the
structural design
and analysis when
subjected to
seismic action.”
Compatibilization standards of architectural
and structural designs
• Flexible floor: Arises when a floor
is reduced considerably in
relation to the contiguous floor.
• This is solved by avoiding flexible
floor in architectural design.
• In cases where a floor with large
separations is needed, the floor
should be located outside the
tower site or it should be the last

Pseudo-resonance
• Occurs when the
period of a building
resembles the
predominant period
of the foundation
soil, a situation that
leads to an increase
in the seismic
effects.
• The use of compact
and homogenous
spatial shapes
during architectural
design can be used
in preventing the
situation.

Seismic torsion
• Produced when
there is no
coinciding between
the Torsion Center
and Stiffness
Center resulting
into extra
constraints mostly
in elements, which
are distant from
the Stiffness
Center.
• This may lead to stepping of the
seismoresistant capacity of the building.
• The morphological solution entails the
design of building with plans and elevations
that are asymmetrical.

Building Collision
• Occurs when
there exists no
joints between
contiguous
buildings and the
collision is
generated when
there is no
synchronization
of the
oscillations.
• This can be avoided through building
separation with consideration given to the
functionalities of the separated bodies
(Cruz, 2015, p.252).

Short columns
• The change in seismic
shear is inversely
proportional to the
cube of the height of its
columns of equivalent
cross sectional area.
• The situation is not any
better for short
columns as concrete is
not suitable for
resisting relatively
strong tangential
stresses hence a
decrease in its ductility
(Steinbuch, 2015,
p.318).
• Appropriate design and
location of the various
openings and spaces serve as
the morphological solution to
the problem.

Concentrated
weight
• There is a
proportional
increase in the
seismic confident
with an increase
in the levels of
the floors relative
to the ground
floor.
• This calls for the avoidance of heavy materials,
coverings, and subfloor and partitioning walls
in the upper levels to reduce the dead weight
of such levels. S
• till, sites designed for heavy equipment,
swimming pool and archives should be at the
lowest levels possible.

• Others include:
 Stiffness-Flexibility
 Sudden change in stiffness in plan and
elevation
 T, L and U-shaped buildings

References
• Cruz, H., 2015. Historical Earthquake-Resistant
Timber Framing in the Mediterranean Area: HEART
2015. 4th ed. London: Springer.
• Steinbuch, R., 2015. Bionic Optimization in Structural
Design: Stochastically Based Methods to Improve the
Performance of Parts and Assemblies. 3rd ed. New
York: Springer.
• Altenbach, H., 2013. Mechanics and Properties of
Composed Materials and Structures. 4th ed.
London: Springer Science & Business Media.
• Manohar, S., 2015. Seismic Design of RC
Buildings: Theory and Practice. 3rd ed. New
Delhi: Springer.