1. What is compaction?
 A simple ground improvement
technique, where the soil is densified through
external compactive effort.
COMPACTION
Compactive effort
+ water =

2.  There are three method in field compaction
 Rolling
 Ramming
 Vibration

3.  Rolling - a heavy cylinder is rolled over the
surface of the soil. Commonly used on sports
pitches. Roller-compactors are often fitted
with vibratory devices to enhance their ability.
 Different types of rollers are used for
Compaction. which are depend on following
factors
 Contact pressure
 Number of passes(normally 5 to 15)
 Layer thickness (less than 15 cm)
 Speed of roller

4.  A hand operated rammer consist of a block of
iron,about 3 to 5 kg in mass,attached to a wooden
rod.the rammer is lifted for about 0.30 m and dropped
on the soil to be compacted
 A mechanical rammer is operated by compressed air or
gasoline power.it is much heavier about 30 to 150 kg.
mechanical rammers have been used up to a mass of
1000 kg in some special cases.
 Tampers are used to compact soil adjecent to
existing structures or confined area as
trenches,within plinth of building.

5.  Vibration are induced in the soil during compaction.the
compactors are available in a variety of forms.when the
vibrator is mounted on adrum,it is called a vibratory roller.
these rollers are available both as pneumatic type and the
smooth wheel type.in a smooth wheel type, a separate motor
drives an arrangement of eccentric weights to create high
frequency,low-amplitude,up and down osicillations of the
drum.
 These rollers are suitable for compacting granular soils.
 Another form of vibratory compactor is a vibrating plate
compactor. hand operated vibrating plates are also available.

6. Instrument of Filed Compaction
 Different types of rollers (clockwise
from right):
 Vibratory roller
Pneumatic rubber tired roller  Smooth-wheel roller
 Sheepsfoot roller

7. Smooth Wheeled Roller
Compacts effectively only to 200-300 mm;
therefore, place the soil in shallow
layers (lifts)

8. Vibrating Plates
 for compacting very small areas
effective for granular soils

9. Sheepsfoot Roller
 Provides kneading action; “walks out” after
compaction
Very effective on clays

10. Impact Roller
 Provides deeper (2-3m) compaction. e.g., air
field

11. Laboratory Compaction Test
- to obtain the compaction curve and define
the optimum water content and maximum
dry density for a specific compactive effort.
hammer
Modified Proctor
Standard Proctor
•5 layers
•3 layers
• 25 blows per
• 25 blows per layer layer
•4.9 kg hammer
•2.7 kg hammer
• 450 mm drop
• 300 mm drop
1000 ml compaction mould