Vibratory ground improvement techniques

4.5.9Granular material

Granular material for raising site levels before treatment, or adding during deep compaction, shall be suitable for compaction and, unless appropriate precautions are taken, be free from hazardous materials.

The grading of material for adding during deep compaction should be within Zone A of Chart 1. Well graded, inert fill which passes a 100mm x 100mm screen in all directions and contains less than 10% fine material of silt or clay size will generally be acceptable for raising site levels.

Precautions, including testing where appropriate, should be taken where hazardous materials are present in fill.