Seismic activity occurs everyday all around the earth. With the growing
number of mega structures, it is necessary to have protection. This protection
is not just for the sake of saving a couple billion dollars to rebuild or repair
a structure, but also serves to save human lives.
The method of protection emphasized here is using dampers to keep a building
from collapsing.
There are three different types of dampers:
Passive - This type of damper does not need any external energy to work.
Passive dampers may be cheaper, but have limited flexibility to meet a
building’s needs.
Active - An active damper uses large amounts of external energy to
operate. This damper pushes on the building to counteract the motion of the
structure. As the building sways one way, the damper pushes in the opposite
direction.
Semi-Active - This type does not need much power and is fully
controllable. Semi-active dampers do not push on the building, they only
counteract the swaying of it by moving their weight the opposite way of the
building’s motion.
Damper Video
(Dramatization)
Once sensors on the building detect motion, the dampers begin to sway to help
the building absorb the vibrations. Using dampers will make the vibrations last
longer, therefore decreasing the amount of energy being released per vibration.
Different size buildings require different arrangements of dampers; there may be
hundreds in a single building or just a few.
Here is a photo of the world’s largest damper, in the Taipei 101.
