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Seismic protection of a student dormitory with BCS
Base Control System (BCS) for student apartment in Mendoza Argentina
The Mendoza Campus of the Technical National University of Argentina commissioned in 2004 the construction of a set of buildings with the main purpose of providing housing facilities to their students. The Mendoza province is located in the western part of Argentina, in the most seismically active region of the country. Two of the dormitory buildings constructed in the Mendoza Campus were identically designed and built. One of them should be placed on an earthquake protection system.
Challenge
The peak ground acceleration according to the national standard
is 0.35 g and for the seismic qualification all recorded earthquakes,
shown in Table 1 had to be taken into consideration. Two different
seismic protection systems were compared with the unprotected
structure. One system represented a typical 2-D base isolation
system – with a vertical stiff support and a horizontal frequency of
about 0.4 Hz. The other system consisted of helical steel springs
and viscous dampers – providing flexibility and damping in all three
directions.
As a result of this study all structural responses were collected
and compared. Special attention was paid to internal stresses and
subsoil demands. The University required a significant reduction of
e.g. the seismic accelerations and internal stresses of the building
with seismic protection measure. Furthermore, it was planned
to install seismic accelerometers in both buildings (with / without
mitigation measure) to be able to directly measure and compare the
different behaviour under seismic loading.
Solution
After comparing the results of two different earthquake protection systems the decision was taken in favour of the Base Control System (BCS).
The building was constructed with reinforced concrete frames and walls of reinforced masonry. Its dimensions are 8.2 by 8.7 m in plan, with a total height of 8.6 m and a total weight of 3,200 kN.
The building has a peripheral beam located at the base whose function is transmitting the loads to the four sets of protection devices located
under each corner of the building foundation. Each set of devices consists of a spring element and a viscous damper (see picture below).
The vertical frequency amounts to about 3.6 Hz and a damping ratio of about 5 %. The authoritative horizontal frequency was chosen to about
1.4 Hz with a damping ratio of more than 20 %.
Technical Facts:
Design Load: 3,200 kN
Vibration Source: Seismic
Support frequency: 3.6 Hz
GERB solution: Prestressable spring elements and Viscodamper® as Base Control System (BCS)
Result
The seismic design of the apartment building using a Base Control System (BCS) was successful. Measurements during a seismic event verified the significant efficiency of the BCS regarding the reduction of seismic demands compared to an identical, unprotected structure.
In 2006 it was possible to measure the seismic response of the base-controlled building at Mendoza in direct comparison to the identical adjacent structure without spring and dampers, as both buildings are permanently equipped with seismic accelerometers. The accelerometers recorded the response due a 5.7 magnitude earthquake that shook the buildings on August 5, 2006.
The direct comparison of the two systems under this same seismic event with a peak ground acceleration of about 0.12 g showed a significant
reduction of acceleration at the top of the building. At the building with Base Control System the acceleration values are reduced by more than
70 % as shown in the diagramms below.
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Further Resources
You need further information on this topic?
Please do not hesitate to contact us with your individual question.
One of our project engineers will get back to you shortly.
Seismic protection of a student dormitory with BCS
Base Control System (BCS) for student apartment in Mendoza Argentina
The Mendoza Campus of the Technical National University of Argentina commissioned in 2004 the construction of a set of buildings with the main purpose of providing housing facilities to their students. The Mendoza province is located in the western part of Argentina, in the most seismically active region of the country. Two of the dormitory buildings constructed in the Mendoza Campus were identically designed and built. One of them should be placed on an earthquake protection system.
Seismic protection of a student dormitory with BCS
Base Control System (BCS) for student apartment in Mendoza Argentina
The Mendoza Campus of the Technical National University of Argentina commissioned in 2004 the construction of a set of buildings with the main purpose of providing housing facilities to their students. The Mendoza province is located in the western part of Argentina, in the most seismically active region of the country. Two of the dormitory buildings constructed in the Mendoza Campus were identically designed and built. One of them should be placed on an earthquake protection system.
Challenge
The peak ground acceleration according to the national standard is 0.35 g and for the seismic qualification all recorded earthquakes, shown in Table 1 had to be taken into consideration. Two different seismic protection systems were compared with the unprotected structure. One system represented a typical 2-D base isolation system – with a vertical stiff support and a horizontal frequency of about 0.4 Hz. The other system consisted of helical steel springs and viscous dampers – providing flexibility and damping in all three directions.
As a result of this study all structural responses were collected and compared. Special attention was paid to internal stresses and subsoil demands. The University required a significant reduction of e.g. the seismic accelerations and internal stresses of the building with seismic protection measure. Furthermore, it was planned to install seismic accelerometers in both buildings (with / without mitigation measure) to be able to directly measure and compare the different behaviour under seismic loading.
Solution
After comparing the results of two different earthquake protection systems the decision was taken in favour of the Base Control System (BCS). The building was constructed with reinforced concrete frames and walls of reinforced masonry. Its dimensions are 8.2 by 8.7 m in plan, with a total height of 8.6 m and a total weight of 3,200 kN.
The building has a peripheral beam located at the base whose function is transmitting the loads to the four sets of protection devices located
under each corner of the building foundation. Each set of devices consists of a spring element and a viscous damper (see picture below).
The vertical frequency amounts to about 3.6 Hz and a damping ratio of about 5 %. The authoritative horizontal frequency was chosen to about
1.4 Hz with a damping ratio of more than 20 %.
Technical Facts:
Design Load: 3,200 kN
Vibration Source: Seismic
Support frequency: 3.6 Hz
GERB solution: Prestressable spring elements and Viscodamper® as Base Control System (BCS)
Challenge
The peak ground acceleration according to the national standard
is 0.35 g and for the seismic qualification all recorded earthquakes, shown in Table 1 had to be taken into consideration. Two different seismic protection systems were compared with the unprotected
structure. One system represented a typical 2-D base isolation system – with a vertical stiff support and a horizontal frequency of about 0.4 Hz. The other system consisted of helical steel springs and viscous dampers – providing flexibility and damping in all three directions.
As a result of this study all structural responses were collected and compared. Special attention was paid to internal stresses and subsoil demands. The University required a significant reduction of
e.g. the seismic accelerations and internal stresses of the building with seismic protection measure. Furthermore, it was planned to install seismic accelerometers in both buildings (with / without mitigation measure) to be able to directly measure and compare the different behaviour under seismic loading.
Solution
After comparing the results of two different earthquake protection systems the decision was taken in favour of the Base Control System (BCS). The building was constructed with reinforced concrete frames and walls of reinforced masonry. Its dimensions are 8.2 by 8.7 m in plan, with a total height of 8.6 m and a total weight of 3,200 kN.
The building has a peripheral beam located at the base whose function is transmitting the loads to the four sets of protection devices located under each corner of the building foundation. Each set of devices consists of a spring element and a viscous damper (see picture below).
The vertical frequency amounts to about 3.6 Hz and a damping ratio of about 5 %. The authoritative horizontal frequency was chosen to about 1.4 Hz with a damping ratio of more than 20 %.
Technical Facts:
Design Load: 3,200 kN
Vibration Source: Seismic
Support frequency: 3.6 Hz
GERB solution: Prestressable spring elements and Viscodamper® as Base Control System (BCS)
Result
The seismic design of the apartment building using a Base Control System (BCS) was successful. Measurements during a seismic event verified the significant efficiency of the BCS regarding the reduction of seismic demands compared to an identical, unprotected structure. In 2006 it was possible to measure the seismic response of the base-controlled building at Mendoza in direct comparison to the identical adjacent structure without spring and dampers, as both buildings are permanently equipped with seismic accelerometers. The accelerometers recorded the response due a 5.7 magnitude earthquake that shook the buildings on August 5, 2006.
The direct comparison of the two systems under this same seismic event with a peak ground acceleration of about 0.12 g showed a significant reduction of acceleration at the top of the building. At the building with Base Control System the acceleration values are reduced by more than 70 % as shown in the diagramms below.
Result
The seismic design of the apartment building using a Base Control System (BCS) was successful. Measurements during a seismic event verified the significant efficiency of the BCS regarding the reduction of seismic demands compared to an identical, unprotected structure.
In 2006 it was possible to measure the seismic response of the base-controlled building at Mendoza in direct comparison to the identical adjacent structure without spring and dampers, as both buildings are permanently equipped with seismic accelerometers. The accelerometers recorded the response due a 5.7 magnitude earthquake that shook the buildings on August 5, 2006.
The direct comparison of the two systems under this same seismic event with a peak ground acceleration of about 0.12 g showed a significant
reduction of acceleration at the top of the building. At the building with Base Control System the acceleration values are reduced by more than
70 % as shown in the diagramms below.
Share this post
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Further Resources
You need further information on this topic?
Please do not hesitate to contact us with your individual question.
One of our project engineers will get back to you shortly.
Further Resources
You need further information on this topic?
Please do not hesitate to contact us with your individual question.
One of our project engineers will get back to you shortly.