Associate Professor in Civil Engineering, Carnegie Institute of Technology, Pittsburgh, Pa
Pages: 25 Published: Jan 1954
Vibration and sudden shocks are known to change a sand deposit from a loose to a dense state. This change is accompanied by surface settlements that approach 1 in. per ft of depth of sand deposit. Compaction by vibroflotation is an effective method of overcoming the settlement prior to construction. The compaction of a loose sand by vibroflotation is a result of two motions: an impulsive radial movement that pushes the sand, and vibratory motions. Field density results are presented to show the effectiveness of the method. The amount of compaction denoted by relative density decreases exponentially as the radial distance from the vibroflot increases. Effect of compaction pattern and spacing of the vibroflot on the densification of sand is given. The maximum and minimum dry unit weights required for design and field control are discussed, as are standard test procedures for minimum and maximum dry unit weight, needed for good design and control.
Paper ID: STP49608S