History Of Piling
In the early days of civilisation[2], from the communication, defence or strategic point
of view villages and towns were situated near to rivers and lakes. It was therefore
important to strengthen the bearing ground with some form of piling.
Timber piles were driven in to the ground by hand or holes were dug and filled with
sand and stones.
In 1740 Christoffoer Polhem invented pile driving equipment which resembled to
days pile driving mechanism. Steel piles have been used since 1800 and concrete
piles since about 1900.
Pile foundations have a rich history dating back to ancient times when they were utilised
to provide support for structures erected on soft soils. In Switzerland, there exists an
ancient city approximately 6000 years old, where wooden piles were constructed to hold
the buildings.
Moving forward to the Roman era, we find that piles, crafted from either stone or timber,
were commonly employed to support bridges, aqueducts, and other architectural
wonders. One of their most iconic achievements was the Colosseum, an engineering
marvel which relied on piles for its solid foundation and was built during the first century
AD.
As time progressed into the Middle Ages, pile foundations remained an essential element in
European construction, providing vital support to structures such as cathedrals and
castles. These foundations mainly consist of wooden piles driven into the ground using
hefty hammers.
The 19th century brought significant advancements to pile foundations due to the
introduction of novel materials like concrete and steel, with the advent of steam-powered
pile drivers, driving piles deeper than ever to support heavier loads.
The 20th century marked yet another milestone for pile foundations with the invention of
hydraulic pile drivers and other specialised equipment. Today, pile foundations have
worldwide applications in various structures, including skyscrapers, bridges, and other
projects requiring a sturdy base on soft or unstable soil.
In Nepal, Timber Piles are also seen used in history for the structure built close to river and
soft soil. The application of cast in situ Pile is started about 25 to 30 years back with the
demand of multi storied building and bridges. Initially hand auger was widely used for drilling
in Kathmandu valley for Piling in soft soil. With increase in demand of Piling DMC and Truck
mounted rig are in operation to this date. In recent years (10 -12 years) High-capacity Piling
equipment’s are widely used in Nepal for bridge & Building projects. Numerous of highcapacity Piling rigs are currently deployed Kanchanpur-Kamala Road Improvement Project,
Kathmandu- Terai /Madesh ast Track Project. At some bridge site, manual excavation for Piling
for large diameter (2.2m) is also reported in Nepal.
Pile Types Based on Load-bearing
Principle
Friction Piles
Friction piles, also known as floating piles, use their whole skin to transfer the structural
loads into the ground. They are used where you can’t find strong stratum at achievable
depths. These piles use the phenomenon of friction to interlock themselves with the
surrounding soil and transfer their loads. Owing to this interlocking, they seem to be
suspended; that is why they are called floating piles.
End-Bearing Piles
End-bearing piles use sturdy and resilient stratum of the soil to transfer heavy structural
load to the ground. They are constructed where you can find a strong enough layer of
rocks at an achievable depth. They are called end-bearing piles because the load is only
transmitted through both ends rather than the whole skin of the piles.
Pile Types Based on Piling Technique
Bored Piles
These piles are constructed by digging a borehole and removing the soil to install or
construct a pile. This technique is used where engineers find sufficiently compacted and
cohesive soil to support the heavy loads of the building.
Driven Piles
Driven piles, on the other hand, are inserted into the ground, without removing the soil,
with the use of hydraulic hammers or pile-driving machines. These piles compact the
surrounding soil while they are driven into the ground. This technique is used in such a
situation where the soil is not compacted enough to support a friction pile.
Pile Types Based on Construction
Materials
Timber Piles
Timber, as we have mentioned earlier, is the oldest known material that has been used
for piling. Timber is readily available and provides durability and economy. However,
timber piles can support a limited amount of structural load and require proper
seasoning and treatment before installation.
Concrete Piles
Concrete is a highly strong material and can bear extreme compressive loads under any
condition. Its discovery opened the doors to new possibilities and revolutionised the
construction rulebooks completely. However, the concrete is a brittle material with low
tensile strength which makes it a weak choice for lateral loads.
Steel Piles
Steel piles, due to high strength and density, usually have a very small cross-section,
which makes it easy to drive them into the ground. Steel piles can be made in different
shapes, such as H, L and T sections or cylindrical shapes. They, however, can corrode
under extreme chemical conditions of the soil and require proper treatment before
installation.
Composite Piles
Composite piles are basically a combination of more than one piling material. Such as
reinforced concrete piles are constructed by combining steel and concrete to achieve high
compressive as well as tensile strength to handle extreme vertical and lateral loads of the
building.