Piling is an essential
process in construction that provides the foundation and support for buildings
and various structures. Over the years, significant advancements have been made
in piling techniques, resulting in improved efficiency, cost-effectiveness, and
sustainability.
Traditional piling methods
like driven piles, such as timber, concrete, and steel piles, and bored piles,
which involve drilling into the ground and filling the hole with concrete have
served the industry well but innovations in piling have brought about new
possibilities.
Pioneering engineers and architects
have introduced a series of ground breaking advancements in piling techniques.
From the utilization of new materials to the introduction of innovative
machinery, these advancements have revolutionized the field of piling, paving
the way for safer, more efficient, and structurally superior foundations.
Zero
Trim Pile Technique
Standard practice for bored
concrete pile construction is to over-pour the concrete and crop the piles down
after curing to ensure they are sound at cut-off level. Breaking out the excess
concrete in this traditional method can cause a lot of health problems to
workers, including hand-arm vibration syndrome, hearing loss and silicosis.
The zero trim pile
technique eliminates the need for cropping by sucking out wet concrete above
cut-off level. The new zero trim pile technique uses a vacuum excavator to suck
out excess concrete when still wet rather than wait for it to set and then cut
it out. Eliminating the need to break out excess hard concrete makes the
process safer and quicker.
This technique could be
transformational for the construction sector, reducing the health risk that
results from breaking piles. There are also other positive benefits of this
technique. Zero trim uses significantly less concrete, leading to significant
improvements in carbon reduction. Zero trim also reduces the time required on
site and, through not having to break-out excess concrete, is significantly
quieter.
Press-in
Piling Method
The decreasing availability
of land in urban areas, and the increasing demand for urban development is
leading to the construction of taller and heavier buildings at increasingly
marginal sites. However, the urban environment is not suited to pile driving.
Conventional dynamic installation techniques (i.e. drop hammer or vibro-piling)
induce vibrations and settlement in a zone close to the pile, and cause noise
and dust pollution. Pile driving vibrations thus damages the existing
structures in urban areas.
Press-in piling method
provides an alternative method for installing pre-formed tubular or sheet piles
into the ground without vibration and with minimal noise impacts using static
loading generated from hydraulic rams. The reaction force is derived from the
extraction resistance of previously installed piles. This allows for the
utilization of relatively small press-in machines which generate a greater
force by homogenizing with the ground.
Different types of press-in
piling machines are able to install steel sheet and pipe piles within various
types of constraints including low headroom, limited side clearance,
accessibility, marine conditions, and other types of constraints in which
press-in machines can eliminate the necessity of temporary work.
The press-in piling method
is particularly suited for retrofit renewal of existing structures where the
disruption of existing services must be avoided. Press-in pilers are capable of
operating alongside live railways for embankment pile stabilisation and beneath
bridge structures for pier strengthening.
Screw
Piles
Screw piles, also known as
helical piles or screw anchors, has gained significant recognition for its
efficiency and reliability. This innovative piling method involves driving
hollow steel piles into the ground using a hydraulic motor. As the piles
penetrate the soil, they create a circular "screw" shape, providing
excellent load-bearing capacity.
A screw pile consists of
several essential components. The shaft, typically made of high-quality steel,
forms the main body of the pile and is responsible for transferring the load to
the ground. Attached to the shaft is a helical plate, which resembles a large
screw or auger. The helical plate acts as an anchor, securely gripping the soil
and providing additional stability to the pile. Lastly, a pile cap is placed on
top of the pile to distribute the load evenly and facilitate the connection
with the superstructure.
Screw piling offers several
distinct advantages over traditional foundation methods. Firstly, the
installation process is efficient and time-saving, as it does not require
extensive excavation or curing time. This results in reduced construction
timelines and cost savings. Additionally, screw piling is highly versatile and
suitable for various soil conditions, including sandy, clayey, and rocky soils.
It can also be used in areas with restricted access or environmental
constraints.
Another notable advantage
of screw piling is its ability to achieve high load-bearing capacities, making
it suitable for both light and heavy structures. The helical plates enhance the
pile’s bearing capacity by increasing the contact area with the soil, ensuring
stability and resistance against lateral forces. Moreover, these piles can be
easily removed and reused, making them a sustainable choice for foundation
construction.
Micropiles
and Mini Piles
Micropiles, also called
mini piles, are slender piles with diameters typically ranging from 100mm to
300mm. Despite their small size, these piles offer exceptional load-bearing
capacity and are ideal for projects where space is limited or access is
restricted, as they require smaller installation equipment. Micropiles are
often used to reinforce existing foundations or provide additional support in
challenging soil conditions.
Micropiles are particularly
effective in areas where traditional pile installation methods are impractical.
Their small size allows them to be installed in tight spaces or areas with
underground utility networks, making them an ideal choice for foundation
construction in densely populated urban areas.
They can be installed at
varying angles i.e. from vertical to obtuse and are highly capable of resisting
both lateral and axial loads due to the fact that they are made of steel with
varying diameters.
Micro piles has the
capability of combining micro pile technology with one or more of the other
ground improvement techniques to meet unique or complex project requirements
cost effectively and efficiently.
Micropiles are being used today for a variety of applications and are becoming a more mainstream method of supporting and re-supporting foundations, seismic retrofits, stabilization of slopes and even earth retention. Micropiles have been used effectively in many applications of ground improvement to increase the bearing capacity and reduce the settlements particularly in strengthening the existing foundations.
