Present by jeetendra and rahul

1. SOIL COMPACTION
SUBMITTED TO :
DR. RAJIB SARKAR
GROUP MEMBER:
 1.JAY PRAKASH TAK (2013UCE1541)
 2.JITESH KUMAR (2013UCE1567)
 3.HIMANSHU PATEL (2013UCE1595)
 4.RAHUL SINGH (2013UCE1556)

2. WHAT IS COMPACTION
In geotechnical engineering, soil compaction is
the process in which a stress applied to a
soil causes densification as air is displaced from
the pores between the soil grains.

3. EFFECT OF COMPACTION ON SOIL STRUCTURE
1. THE WATER CONTENT AT
WHICH THE SOIL IS
COMPACTED PLAYS AN
IMPORTANT ROLE IN SOIL
STRUCTURE
2. SOIL COMPACTED AT WATER
CONTENT LESS THAN OPTIMUM
WATER CONTENT HAVE
FLOCCULATED STRUCTURE
3. SOILS COMPACTED AT WATER
CONTENT MORE THAN
OPTIMUM WATER CONTENT
HAVE DISPERSED STRUCTURE

4. Why Soil Compaction ????
1- Increase Soil Strength
2- Reduce Soil Settlement
3- Reduce Soil Permeability
4- Reduce Frost Damage
5- Reduce Erosion Damage

5. Factor Affecting Soil Compaction
1.SOIL TYPE
2.WATER CONTENT (WC)
3.COMPACTION EFFORT REQUIRED(ENERGY)

6. LABORATORY TEST FOR SOIL
COMPACTION
1.STANDARD PROCTER TEST
2.MODIFIED PROCTER TEST

7. Results of Laboratory Tests
Sr. No. Laboratory Test Result
1 Grain Size Distribution 74.69% fine
2 Specific Gravity (G) 2.65
3 Water Content (Natural) (w) 9.29%
4 Liquid Limit (WL) 56.50%
5 Plastic Limit (WP) 29.10%
6 Plasticity Index (IP or P.I) 27.40%
7 Free Swell Index (F.S.I) 30
8
Optimum Moisture Content
(O.M.C.) 20.02%
9 Maximum Dry Density (M.D.D.) 1.63 g/cc
10 California Bearing Ratio (C.B.R.) 2.33%
11
Unconfined Compressive Strength
(U.C.S.) at OMC 2.69 Kg/cm2

8. Types of compaction
1- Vibration(Vibratory Force Compaction)
2- Impact (Vibratory Force Compaction)
3- Kneading (Static Compaction)
4- Pressure(Static Compaction)

9. Soil Compaction in the
Field:
1- Rammers
2- Vibratory Plates
3- Smooth Rollers
4- Rubber-Tire
5- Sheep foot Roller
6- Dynamic Compaction

10. BENEFIT OF COMPACTION
1. Increase Load-bearing Capacity
2. Prevents Soil Settlement (Better Stability)
3. Reduce Water Seepage
4. Reduces Shrinkage

11. CASE STUDY
SOIL BEARING CAPACITY IN BLACK COTTON SOIL
Case Study Site Location
Solapur Road, Keshwapur, Hubli
Purpose:
• To procure soil samples for assessing the
physical properties, which will help in design
and mode of construction of proposed
foundation.
• To determine the nature, thickness and
variation of soil strata in the region.

12. SITE INVESTIGATION

13. THEORY-
1. Black cotton soils and other expansive
soils have typical characteristics of
shrinkage and swelling due to moisture
movement through them.
2. During rainy season, moisture
penetrates into these soils, due to which
they swell.

14. THEORY CONTI…
1.Most of the fine grained clays, including
black cotton soils have their grains which
are more or less in the form of sheets , and
their grains are not round.
2.When moisture enter between the
platelets under some hydrostatic pressure,
the particles separate out, resulting in
increase in the volume. This increase in
volume is commonly known as swelling.

15. 3.During summer season, moisture moves
out of the soil and consequently, the soil
shrinks. Shrinkage cracks are formed on the
ground surface

16. PROPERTIES OF BLACK COTTON SOIL-
1. CLAYEY
2. THEY SWELL AND BECOME STICKY WHEN
WET AND SHRINK WHEN DRIED
3. DURING DRY SEASON, THESE SOILS
DEVOLOP WIDE CRACKS.
4. RICH IN LIME AND IRON, NITROGEN AND
ORGANIC MATTER

17. METHODS OF INCREASING SOIL BEARING
CAPACITY OF BLACK COTTON SOIL
1) Increasing Depth of Foundation:
In granular soil the bearing capacity increases with the depth
due to the confining weight of overlying materials.
2) Compaction of soil:
Due to the compaction of soil the bearing capacity of the soil
increases resulting in reduction in resting settlements
3) Drainage of soil:
Due to the presence of water in the soil the bearing capacity
of the soil is decreased hence by draining out water the void
ratio is improved resulting in higher bearing capacity.

19. 4) Grouting:
Bore holes in sufficient numbers are driven in the ground
and cement grout is forced through these under pressure
Due to which the bearing capacity of soil is increased.
5) Chemical Treatment:
In this treatment certain chemicals are grouted in the
place of cement grout. The chemical used is such that it
can solidify and gain early strength.

21. Safety Analysis for Soil Bearing
Capacity Of Black Cotton Soil
1. The foundation should be taken at Ieast 50 cm
lower than the depth of moisture movement. This
depth should also be much more than depth of
tension cracks.
2. Where this soil occurs only in top layer, and where the
thickness of this layer does not exceed 1 to 1.5 m, the
entire layer of black cotton soil (or other expansive soil)
should be removed, and the foundation should be laid on
non-shrinkable non- expansive soil.

22. Conclusion:
Scope of the work was to Study the Soil
Bearing Capacity and Properties of Black
Cotton Soil for Civil Engineering works.
 Following conclusions are made on the basis of
test results
The property of volumetric changes with the
change of atmospheric conditions makes black
cotton soil dangerous to be founded buildings.

23.  It swells excessively when wet and shrinks
excessively when dry resulting terrible
cracks in soil without any warning.
Hence due to the low Bearing Capacity of Black cotton soil
which makes it dangerous for construction of high rise
buildings. So all the safety and precautionary methods
must be followed before construction of the building.