Soil improvement and construction methods in peat - Geotechnics of Organic Soils and Peat - page 169

Table 6.5 (a) Analysis of the effectiveness of the various foundation techniques

Pile Pile Pile Strength Compressibility

Special spacing diameter depth increase decrease

Technique equipment (m) (m) (m) (%) (%)

Limit piles * 1-2 0.3-0.5 3 40-70 25-50

Lime/cement columns Required * 1-2 0.5-3.5 30 1,000-5,000 40-60

Compacted sand piles Required * 1.5-2.2 0.5-1.5 15 400-500 in 30-50

max. 2 clay 30-70

in peat in peat

Stone columns Required * 1.2-3.0 0.6-1.0 5 400-500 80

(b) Application of methods to soil types ( after McManus et al ., 1997)

Deep improvement technique Soft clays Peat Organic soils with high water content

Lime piles

Lime columns

Lime/fly ash column

Lime/gypsum column

Cement column

Compacted sand pile

Stone column

* Modified standard bored piles equipment

• For deposit of greater than 10m, one of the deep stabilization techniques, including

the pile support method, can be considered.

Analysis of the effectiveness of the various foundation techniques and application
of methods to soil types is included in Table 6.5.