2. Method invented and developed by MenardCompany in Late 1960s
Dynamic Compaction has been used on thenumerous sites all over the
world for varioussoil conditions and for a variety ofapplications
such as: roads, airports, largehalls 3. Technique involves
repeatedly dropping a largeweight from a crane Weight may range
from 6 to 172 tons Drop height typically varies from 10 m to 40m 4.
Degree of densification achieved is a function of the energyinput
(weight and drop height) as well as the saturation level,fines
content and permeability of the material 6 30 ton weight can
densify the loose sands to a depth of 3m to 12 m 5. Hook Boom Hoist
Rope Kingpost Crawler Load cell Cab andcontrol
CounterweightHookHoistropeBoomKingpostcrawlerLoad cellCab
andcontrolCounterweight 6. Dynamic compaction is done in 3 phases
:- Phase one Phase two Phase three Each phase can have no of
passesprimary, secondary, tertiary, etc. 7. Spacing between impact
points depend upon: Depth of compressible layer Permeability of
soil Location of ground water level Deeper layers are compacted at
wider grid spacing, upperlayers are compacted with closer grid
spacing 8. Deep craters are formed by tamping Craters may be filled
with sand after each pass Heave around craters is generally small
9. Applicable for all type of granular soil This technique is
particularly well adapted tonon-organic, non-homogeneous fill
andreclamation areas with variable characteristics It is effective
in both saturated and un-saturatedsoils. The depth of the
compaction most oftenvaries between 3.0 and 7.0 m. 10. Expensive
and time consuming Shock waves affect underground utilities
indeveloped areas The soil can be treated as close as 3 m
fromunderground services and can be treated 6 mfrom the sound
structures Causes environmental pollution by makingnoise, gusts of
air, vibrations
