A history of vibratory deep compaction 21
The new method was called vibro flotation in the United States. It only
gained full recognition in the early 1950s after the Bureau of Reclamation
reported vibro flotation experiments at Enders Dam (1948) and particularly after D’Appolonia (1954) had published his article, “Loose sands—
their compaction by vibroflotation.”
The vibrator or Vibroflot, as it was called in the United States, was
equipped, like its German forerunner, with an electric motor and was operated at 1800 rpm developing 30 Hz with a horizontal force of 100 kN at
maximum double amplitude of 19 mm (Figure 2.12). Due to these characteristics, it was ideal for the compaction of sands. The advantages of
vibro flotation were seen in the first instance in its easy and controllable
working method for effectively compacting loose sands. Soon practical recommendations were developed enabling the engineer to design and supervise the compaction works. The main criterion for judging the success of
Figure 2.12 Section through Vibroflot. (Courtesy of Vibroflotation Foundation Company
brochure.)
od|o>
12" I.D
5-0"
2 "
Water to
Upper Je ts
Follow-up Pipe
W ater to
Bottom Je t
Cooling
"W ater
Inlet
15" I.D,
6 '- lf
Eccentric Sh aft
Vibrator
Electric Cable
Upper Je t
Cooling Water.,
Outlet
E le c tric M otor
Universal
Bottom Je t
III"
8
The new method was called vibro flotation in the United States. It only
gained full recognition in the early 1950s after the Bureau of Reclamation
reported vibro flotation experiments at Enders Dam (1948) and particularly after D’Appolonia (1954) had published his article, “Loose sands—
their compaction by vibroflotation.”
The vibrator or Vibroflot, as it was called in the United States, was
equipped, like its German forerunner, with an electric motor and was operated at 1800 rpm developing 30 Hz with a horizontal force of 100 kN at
maximum double amplitude of 19 mm (Figure 2.12). Due to these characteristics, it was ideal for the compaction of sands. The advantages of
vibro flotation were seen in the first instance in its easy and controllable
working method for effectively compacting loose sands. Soon practical recommendations were developed enabling the engineer to design and supervise the compaction works. The main criterion for judging the success of
Figure 2.12 Section through Vibroflot. (Courtesy of Vibroflotation Foundation Company
brochure.)
od|o>
12" I.D
5-0"
2 "
Water to
Upper Je ts
Follow-up Pipe
W ater to
Bottom Je t
Cooling
"W ater
Inlet
15" I.D,
6 '- lf
Eccentric Sh aft
Vibrator
Electric Cable
Upper Je t
Cooling Water.,
Outlet
E le c tric M otor
Universal
Bottom Je t
III"
8