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ENGINEERING BEHAVIOUR OF STABILIZED PEAT SOIL


INTRODUCTION
Peat and organic soil represents the extreme form of soft soil.
At its initial state peat has high compressibility and water holding capacity, low

specific gravity and medium to low permeability .
Consequently it is widely regarded as a problematic soil .
In practice it is economical to stabilize the soil by dry mixing the soil with binder

to form columnar reinforcement in deep peat ground .

DEFENITION
PEAT SOIL
Peat soils are formed by disintegration of plants and organic matters .It is also

formed by slow decay of successive layers of aquatic and semi aquatic plants. Eg:

sedges, reeds and mosses. Peat soil have very high organic content so are very dark,

almost black in hard to roll into a ball.


TYPES OF PEAT SOIL
PEAT MOSS

Peat mosses are derived primarily from sphagnum moss. It is used in agriculture as

poultry and as a soil conditioner and an acidifying agent .It is also used in

industry as an insulating material.

FUEL PEAT


Fuel peat is most widely used in regions where coal and wood are scarce .Eg: Ireland,

Scandinavia and Russia.


PROPERTIES OF PEAT SOIL
Peat soil has high initial void ratio ranging from 8.0 to 9.6.

Loose, porous and light in nature.

High water holding capacity

Good insulating property.

Important raw material in horticulture.



STABILIZATION OF PEAT SOIL
Dry mixing the soil with binder. Deep mixing method of soft soil stabilization is

using successfully in construction industry nowadays .
Mixture of ordinary Portland cement, ground granulated blast furnace slag and

siliceous sand is effective at stabilizing peat soil.


ADVANTAGES
High organic content

Potentially very fertile

Cultivated quite intensively

High water holding capacity




CONCLUSION
Peat soil has unique characteristics and there is a tendency in construction industry

to avoid this type off problematic soil. So peat soil stabilization method is

economical and consume less time can overcome this type of problem. Peat soil has low

bearing capacity and low unconfined compressive strength. Some conventional

laboratory tests were done to determine the physical and mechanical properties of

soil profile .The experimental data can be used to find out a proper ground

improvement method. Now a days deep mixing method for ground improvement especially

by columnar technique in which soil “ cement columns are made by using mixing auger

and using some admixtures its becoming popular .Binder can be provided in dry form as

peat soil has high water content .