10-04-2017, 09:33 PM
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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 .