Screw pile foundations are less expensive than their permanent counterparts, yet they are reliably stable and durable. You simply need to follow installation guidelines and know the correct depth to drive screw piles to ensure reliable support for your building.
Thoughtful design and
no secrets
A foundation is a building's safety net, without which its
lifespan is doomed to be short. Any type of foundation is a carefully
calculated technology with features that provide support advantages under
specific conditions.
Screw piles are installed around the perimeter of the
building, at the intersection of load-bearing partitions, and every 2-3 meters.
These are metal posts, mostly buried in the ground and connected by a grillage
to evenly distribute the load. At the end of each support are
screws—blades—that perform two functions:
•
facilitate
the pile's penetration into the ground;
•
compaction
of rock to improve adhesion and load-bearing capacity.
The trick to this technology is to penetrate the upper,
capricious, frost-heaving soil layers to reach stable ground.
Drive Depth – How to
Determine How Much to Screw In?
There is a set of recommendations that allow you to
determine the most accurate depth for driving a pile. The main determining
factors for drive depth are:
•
the
purpose of the support post and its load-bearing capacity;
•
the
characteristics of the soil layers in the development area;
•
the
nature of soil freezing;
•
the
height of the foundation (if it is a building).
Let's look at each factor in more detail.
Drive Depth Depending
on Purpose
Piles are used to construct a supporting foundation for
various structures, as well as to reconstruct an old foundation that requires
repair or expansion of the existing one.
Since improving the adhesion of the screw post directly
impacts the load-bearing capacity, the drive depth for large structures is
usually greater than for lighter structures such as sheds, fences, and barns.
However, this factor is determined individually at the design stage, taking
into account the characteristics of the development area.
The more complex the soil, the deeper it will
be
In sand, clay, and other similar soil types, as well as in
marshy areas, it is very difficult to erect a building because the soil is
unstable. The solid foundation bulges, sinks unevenly, and drags parts of the
building down with it, destroying it. The use of piles solved this problem, as
it became possible to anchor the supports in the solid ground, bypassing the
problematic soil. A variety of sizes allows for the selection of support posts
of the appropriate length.
Geological surveys or information from the urban planning
authority at the construction site can help determine the soil composition and
the depth of the solid rock.
Frost heave is a trifle for piles
Before the onset of winter, a lot of moisture usually
accumulates in the soil due to autumn rains and the first melted snow. When
temperatures drop below freezing, a process called frost heave occurs. During
this time, the liquid in the upper soil layers turns to ice, and consequently,
its volume increases. The soil protrudes approximately 5-10 cm, pushing out
everything it contains, including the shallow pile foundation.
Plinth Height Above
Ground
This parameter is not related to the screw-in depth, but is
important when choosing the pile length.
From an aesthetic perspective, the cladding is less
important than the detrimental effects of snow cover and marshy areas on the
building's walls. Prolonged exposure to a liquid environment degrades building
materials, even those with low hydrophobicity.
Therefore, when ordering piles, remember to purchase them
not only taking into account the soil freezing depth and the depth of the solid
layers, but also to allow for the height of the plinth.
Comments
Post a Comment