1. th
11 International Conference on Earthquake Resistant Engineering Structures
Protection of Masonry Housing in High Seismic Zones with Low-Cost Rubber Isolators
Ahmad Basshofi Habieb¹, Gabriele Milani¹, Tavio², Federico Milani ³ ¹ABC Department, Politecnico di Milano, Italy
²Institut Teknologi Sepuluh Nopember, Indonesia
³Chem.co Consultant, Occhiobello, Italy
5-7 July 2017
Alicante, Spain

2. Great Earthquakes in Indonesia
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Background
Great Earthquakes in Indonesia
ACEH
9.2 Mw earthquake in followed by tsunami dead
PADANG
7.6 Mw earthquake in dead
JOGJAKARTA
6.4 Mw earthquake in dead
ABC DEPARTMENT - POLITECNICO DI MILANO

3. Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Background
Many developing countries have high-risk seismic zones
Low-class housings in developing countries are often not engineered
masonry structures are commonly found in rural areas
source: Teddy Boen (2013)
ABC DEPARTMENT - POLITECNICO DI MILANO

4. Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Background
Base Isolation is considered as an effective method to improve the seismic behavior of structures
thick steel plate
high damping rubber
steel layer reinforcement
Massive utilization of conventional seismic isolator costs too much for low-class housing
ABC DEPARTMENT - POLITECNICO DI MILANO

5. Vision of this research
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Vision of this research
Develop low-cost isolation system from rubber materials and practical guidelines of its application for housing in developing countries
ABC DEPARTMENT - POLITECNICO DI MILANO

6. Preliminary design of isolator (Target properties)
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Preliminary design of isolator (Target properties)
150 x 150 x 54
5 x tr
4 x tf
FREI - 150
100 x 100 x 54
5 x tr
4 x tf
FREI - 100
fiber lamina reinforce.
no thick steel plate
Rubber A Shore Hardness = Thickness of rubber (tr) = 10 mm
Thickness of fiber (tf) = 1 mm
Vertical load range = 1 – 4 MPa
Max. horizontal deform = 1.75 x tr total
Eff. Damping ratio = %
Unbonded application
FREI - 200
200 x 200 x 76
7 x tr
6 x tf
ABC DEPARTMENT - POLITECNICO DI MILANO

7. Modeling Low Cost Rubber Isolator
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
ICCMSE 2017
Modeling Low Cost Rubber Isolator
carbon fiber with E = 40 GPa
C3D8R element
Equivalent to rubber with shore A hardness = 40
ABC DEPARTMENT - POLITECNICO DI MILANO

8. Modeling Low Cost Rubber Isolator
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Modeling Low Cost Rubber Isolator
Excessive tensile stress
roll-over
Increase the damping ratio (can have 10 %)
roll-over
Permanent sliding damage of isolators
Horizontal behavior of FREI in bonded, unbonded, and frictional conditions
The unbonded one seems the most suitable type for low cost isolation system
ABC DEPARTMENT - POLITECNICO DI MILANO

9. Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
ICCMSE 2017
MODELLING ISOLATORS
Experimental Results of FREI (Toopchi-Nezhad et al, 2008)
Numerical model of FREI-200 with 10% damping
ABC DEPARTMENT - POLITECNICO DI MILANO

10. ISOLATORS FOR MASONRY STRUCTURES
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
ICCMSE 2017
ISOLATORS FOR MASONRY STRUCTURES
masonry
Concrete beam
Rubber isolator
foundation
Application of rubber isolators for masonry
ABC DEPARTMENT - POLITECNICO DI MILANO

11. ISOLATORS FOR MASONRY STRUCTURES
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
ICCMSE 2017
ISOLATORS FOR MASONRY STRUCTURES
First prototype of isolated masonry with unbonded FREI in Tawang, India. (Van Ngo Thuyet et al, 2017)
ABC DEPARTMENT - POLITECNICO DI MILANO

12. Damping ratio 10% (high damping thanks to the unbonded application)
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Numerical simulations of 2-story masonry housing isolated with low-cost seismic isolators (FREI-150)
Thickness of the wall 30 cm
Max vertical load 3.2 MPa
Damping ratio 10% (high damping thanks to the unbonded application)
Step = 1.33 m
ABC DEPARTMENT - POLITECNICO DI MILANO

13. Concrete damage plasticity
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
ICCMSE 2017
Masonry FE Model
Concrete damage plasticity
= 1300 MPa

14. Modal analysis Without isolation With isolation A. B. Habieb et al
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Modal analysis
Without isolation
With isolation
ABC DEPARTMENT - POLITECNICO DI MILANO

15. DS 2 : moderate damage Drift 0.1 %
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Numerical Simulations
Static pushover analysis of isolated 2 story masonry housing
Isolator unstable
DS 2 : moderate damage Drift 0.1 %
DS 3 : extensive damage
Drift 0.3 %
DS 4 : Collapse
Drift 0.5 %
 Calvi et al, 1999

16. Numerical Simulations
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Numerical Simulations
3D Non-linear Dynamic Analysis (in case of L’Aquila accelerogram 0.6g)
no DS 3 in the isolated model
ABC DEPARTMENT - POLITECNICO DI MILANO

17. Isolated model at the end of test
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Numerical Simulations
3D Non-linear Dynamic Analysis (in case of L’Aquila accelerogram 0.6g)
DS 2 (both models)
Isolated model at the end of test
DS 3 (no-isolation)
DS 4 (no-isolation)
Then, we have to monitor the shear behavior of rubber isolators during ground motion
ABC DEPARTMENT - POLITECNICO DI MILANO

18. Control of isolators V F
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Control of isolators
Monitoring the behavior of isolators to check if the deformation limit is reached (when the isolator becomes unstable) V F
Full contact deformation  isolator unstable
Critical bearing area buckling of isolator
Also, the isolators may exhibit deformation with some inclinations
ABC DEPARTMENT - POLITECNICO DI MILANO

19. Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Control of isolators
Behaviors of unbonded FREI-150 in different angles of shear deformation during L’Aquila earthquake
Ut = maximum deformation occurred during ground motion
Ucrit = deformation limit, when the isolator becomes unstable due to full contact deformation
Deformation limit is generally about 175% x tr = 87 mm (without inclination)
With more inclination, the deformation limit decreases

20. Results On going research
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Results
The isolators proposed less expensive than the commercial devices.
Isolation system proposed can reduce significantly the damage of masonry housing
FREI 150 are suitable for two-story masonry housing, the case of seismic motion with PGA=0.6g
The isolator proposed satisfies the limit of horizontal displacement due to earthquake
On going research
Experimental validations
Evaluating the performance of isolated building according to Indonesian seismic code
ABC DEPARTMENT - POLITECNICO DI MILANO

21. THANK YOU

22. Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Research Products
Prototypes of Low-cost fiber reinforced elastomeric isolator (FREI)
Technological procedures of FREI fabrication
Technical guidelines of isolation system for housing using low cost FREI
ABC DEPARTMENT - POLITECNICO DI MILANO

23. Objectives Understand the behavior of rubber isolators
Low cost rubber seismic isolator for housing in development countries
A. B. Habieb et al
Objectives
Understand the behavior of rubber isolators
Develop numerical models and validate through experimental works
Understand the fabrication process of rubber isolators
Optimize the composition of rubber and fiber materials for isolators
Develop practical guidelines of low-cost rubber isolation system for housing
Turer and Ozden, 2008
ABC DEPARTMENT - POLITECNICO DI MILANO