Page 37 - DOUCE HYDRO 2013

37
Improvement
by using PSD
P R O T E C T I O N S
In the previous solutions, the central pier was fixed.
Using STU or dampers help us decrease shear in the fixed pier but, when this pier is
too stiff, their efficiency will be very weak.
If the shear of the fixed pier has to be further decreased, and should it remains fixed
during the earthquake, the solution would be to equip that central fixed pier with a
PSD so that it can move the deck, thus providing larger shear forces in this pier (see
drawing below).
In order to solve this
problem, an elegant
solution is to install a
PSD between the deck
and the pier.
The PSD had 3 functions:
Link the pier to the deck during service. ( Preload force )
Damp energy during the earthquake ( Energy dissipation )
Align the deck after an earthquake.
During earthquake
Before earthquake
After Earthquake
P3