Infill use and compaction

Published on 12 February 2008

Infill embankments are earth structures resulting from utilisation of materials to raise or level the natural terrain. Compaction is the action of tamping a material by mechanical means.

A compactor (all rights reserved)

Infill embankments are earth structures resulting from utilisation of materials to raise or level the natural terrain. It has to be suitable for extraneous needs (road or rail traffic, buildings, superstructures etc.) without it becoming deformed to the detriment of its function (settlement, slippage etc).
The quality of an infill embankment depends on the type of material which it is made of and how the material is used.
Material which originated as site rubble or from a borrow pit must be used at the correct level of water content (to give adequate load-bearing characteristics) and must be compacted (to ensure stability).

Compaction: this is the action of tamping a material by mechanical means (to reduce formation of empty pockets and increase cohesion). It is either carried out using static compactors (with tyres or rammers), which act exclusively due to their own weight, or using vibrating compactors (with smooth drum or rammers) which act both by their own weight and by vibration. The type of materials and the desired degree of compaction determine the type of compactor (and its speed and number of passes) as well as the thickness of the layer to be compacted.
Compaction is controlled either by periodic density measurements ( nucleodensimeter), or by continuous measurement of compaction power output.