Forced Vibration Tests
Intake Tower at Wimbleball Lake,
to see inside view of tower)
Special test machines called "Rotating
Eccentric Mass Exciters" were used to vibrate
the Wimbleball intake
Three of them were lowered into the 50 metre high, reinforced
concrete tower (Show
Me), and bolted down on different floor levels (Show
The tower is connected to the top of the buttress
dam by a bridge. When the tower vibrated, it caused the
bridge and dam to vibrate too. The vibrations of all these
structures were measured using accelerometers.
The movement of the tower also set up small vibrations in
the reservoir water, which caused the water pressures to fluctuate.
The changing water pressure on the face of the tower was
measured with an electronic instrument called a pressure transducer.
Me) The pressure transducer and cable were lowered down
from the top of the bridge
(Show Me) and guided down the face of the tower using
a specially made weighted wheel. (Show Me)