Table F-3
Liquefaction remediation measures (National Research Council, 1985; Ferritto,
1997b).
Maximum
Most Suitable Soil
Relative
Method
Principle
Effective
Conditions/Types
Cost
Treatment Depth
1.
Blasting
Shock waves and vibrations cause
Saturated, clean, sands;
>40 m
Low
limited liquefaction,
partly saturated sands
displacement, remolding, and
and silts after flooding.
settlement to higher density.
2.
Vibratory probe
Densification by vibration;
Saturated or dry clean
20 m routinely
Moderate
a. Terraprobe
liquefaction-induced settlement
sand; sand.
(ineffective above
b. Vibrorods
and settlement in dry soil under
3-4 m depth);
c. Vibrowing
overburden to produce a higher
>30 m sometimes;
density.
vibrowing, 40 m
3.
Vibrocompaction
Densification by vibration and
Cohesionless soils with
>30 m
Low to
compaction of backfill material of
less than 20% fines.
moderate
a. Vibroflot
b. Vibro-
sand or gravel.
Composer
System
4.
Compaction piles
Densification by displacement of
Loose sandy soil; partly
>20 m
Moderate to
pile volume and by vibration
saturated clayey soil ;
high
during driving; increase in lateral
loess.
effective earth pressure.
5.
Heavy tamping
Repeated application of high-
Cohesionless soils best;
30 m
Low
(dynamic compaction)
intensity impacts at surface.
other types can also be
(possibly
improved.
deeper)
6.
Displacement/
Highly viscous grout acts as radial
All soils.
Unlimited
Low to
compaction grout
hydraulic jack when pumped in
moderate
under high pressure.
7.
Surcharge/ buttress
The weight of a surcharge/
Can be placed on any
--
Moderate if
soil surface.
vertical
buttress increases the liquefaction
resistance by increasing the
drains used
effective confining pressures in
the foundation.
Sand, silt, clay.
Gravel and sand
Moderate to
Relief of excess pore water
8.
Drains
high
pressure to prevent liquefaction.
>30 m; depth
a. Gravel
limited by
(Wick drains have comparable
b. Sand
permeability to sand drains.)
vibratory
c. Wick
equipment; wick
Primarily gravel drains; sand/wick
d. Wells (for
may supplement gravel drain or
>45 m
permanent
relieve existing excess pore water
dewatering)
pressure. Permanent dewatering
with pumps.
9.
Particulate grouting
Penetration grouting-- fill soil
Medium to coarse sand
Unlimited
Lowest of
pores with soil, cement, and/or
and gravel
grout
clay
methods
10. Chemical grouting
Solutions of two or more
Medium silts and
Unlimited
High
chemicals react in soil pores to
coarser
form a gel or a solid precipitate.
11. Pressure-injected lime
Penetration grouting-- fill soil
Medium to coarse sand
Unlimited
Low
pores with lime.
and gravel.
F-37
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