1. Northern Technical University
Engineering Technical College / Mosul
Building and Construction Technology Engineering Dept
Earthquake
structures
‘ isolation system ’
Student Name :- Maroof Imad
3. Introduction
The seismic risk mitigation is one of the greatest challenges of the Civil
Engineering and an important contribution toward this challenge can
be given by the Geotechnical Earthquake Engineering. Lesson learned
by recent destructive earthquakes (January 2010 Port-au-Prince region
of Haiti and March 2011 Tohoku Japan), confirms that local soil
conditions can play a significant role on earthquake ground motions.
4.
5. Isolation systems
These mechanisms are intended to separate the structure completely
from its foundation, using rollers, friction pads. Isolators act
essentially as force-limiting devices, since the base shear force in the
structure cannot exceed the limiting friction force in the isolating
mechanism ,
isolation mechanism should satisfy the following conditions :-
1. Relative displacements across the mechanism should be allowed in
all directions, but should be limited to certain tolerable values.
6. 2. Post-earthquake residual displacements should be minimized.
3. Wind should not cause relative motion across the mechanism.
4. Preferably. some energy should be absorbed by the mechanism.
5. Impact type forces generated at the end of the operative range of the
mechanism should be minimized.
6. Manufacture, maintenance and installation of the mechanism should
be as inexpensive as possible.
7. Base Isolation systems
Base isolation offers important advantages over a conventional
protection method because it reduces the earthquake forces
transmitted into a structure. Thus, it protects not only the structure
itself but also the contents and secondary structural features. This is
particularly important for buildings with important contents such as
hospitals or emergency facilities that need to maintain full
serviceability after an earthquake.
10. Base Isolation systems
HDRB
High Damping Rubber Bearing :-
is a simple, cost-effective and maintenance-free device that
provides the isolation interface. They can be designed to withstand
the design earthquakes without significant damage. Three
different rubber compounds are available as standard:
Soft compound (S), with a low modulus (G=0.6 MPa)
Normal compound (N), with a medium modulus (G= 0.9 MPa)
Hard compound (H), with a high modulus = (G=1.1 MPa).
11. 1.is a simple, cost-effective and maintenance-free device that provides the
isolation interface. They can be designed to withstand the design
earthquakes without significant damage.
12.
13. Friction pendulum bearing :-
Another base isolation technique is friction pendulum bearing .These
bearing shield , the structure from seismic energy by using a
pendulum. Typically, a steel ball that rests on a curved surface serves
as a pendulum. The pendulum swings back and forth during an
earthquake, dissipating the energy of the seismic waves.
Base Isolation systems
14. 1.is a simple, cost-effective and maintenance-free device that provides the
isolation interface. They can be designed to withstand the design
earthquakes without significant damage.
15.
16. 1.is a simple, cost-effective and maintenance-free device that provides the
isolation interface. They can be designed to withstand the design
earthquakes without significant damage.
Above Base Isolation systems
TMD
Tuned Mass Damper (TMDs) or vibration absorbers:
– First suggested by Hermann Frahm in 1909.
– Relatively small mass-spring-dashpot systems calibrated to be in
resonance with a particular mode of vibration.
– Usually installed on roofs of buildings.
• TMDs effective in reducing wind-induced vibrations in high-rise
buildings and floor vibrations induced by occupant activity.
• More recently, TMDs considered for seismic protection of buildings.
17. 1.is a simple, cost-effective and maintenance-free device that provides the
isolation interface. They can be designed to withstand the design
earthquakes without significant damage.
18. ISI
Inter-Storey Isolation
is becoming increasingly attractive, as it allows greater
freedom in the structural conception of skyscrapers and
multi-purpose buildings by defining two independent
structures, i.e. substructure and superstructure , the ISI
technique can be applied to add extra storeys on the top of
existing buildings, with appropriate vertical capacity, without
increasing the base shear forces
Above Base Isolation systems
19. 1.is a simple, cost-effective and maintenance-free device that provides the
isolation interface. They can be designed to withstand the design
earthquakes without significant damage.
21. 1.is a simple, cost-effective and maintenance-free device that provides the
isolation interface. They can be designed to withstand the design
earthquakes without significant damage.
Apple Park. Cupertino, California, 445,005
Square meters. Apple’s new corporate
headquarters
is a four-story, ring-shaped building, with a
circumference of 1,512 sqft. and opened in
April 2017
23. Adana Integrated Health Campus, Adana, Turkey, 430,000 square meters
The campus will have a total
capacity of 1,550 beds housed in three hospitals: the 1,300-bed main
hospital, a 150-bed
physical-therapy and rehabilitation hospital and a 100-bed high-security
criminal
psychiatric hospital. The campus is supported by 1,512 base The complex
was designed HWP,
and built by Rönesans Sağlik Yatirim. The structural engineer was Ulker
Engineering Ltd. It
was completed in May, 2017.
.
24. References
1- Earthquake-Resistant Structures – Design,
Assessment and Rehabilitation
Edited by Abbas Moustafa
Published by InTech
Janeza Trdine 9, 51000 Rijeka, Croatia
2- STRUCTURAL SYSTEMS FOR EARTHQUAKE
RESISTANT CONCRETE BUILDINGS
by
Mark Fintel and S. K. Ghosh
Partial Proceedings of the Workshop on ERCBC, July
11-15, 1977
University of California at Berkeley
3- SEISMIC ISOLATION BASE ISOLATORS
Design according to BS FN 15129
4- Chapter 13
Tuned-Mass Dampers
CIE 626 - Structural Control
Chapter 1 - Introduction
CIE 626 Structural Control
Chapter 13 – Tuned-Mass Dampers
5-Seismic Isolated Structures: Concept,
Review, Design and Worldwide
Application
Course No: S03-027
Credit: 3 PDH
Ibrahim M. Metwally, Ph.D., P.E.
