A recent study introduces a dome-plug modular pile design that boosts permafrost foundation strength by 35–63%, enables year-round construction, and allows full, eco-friendly dismantling—offering a high-performance alternative for Arctic modular platforms.
Data from Trushko et al., Geotechnics 2025, 5, 79 – Numerical FEM results on Yamal Peninsula permafrost
Building anything on permafrost is like trying to balance a house on a freezer that’s slowly melting. The Arctic is warming faster than the global average, which means the once-solid frozen ground beneath pipelines, drilling rigs, and industrial platforms is losing its strength. As permafrost thaws, soil structure weakens, foundations shift, and infrastructure becomes vulnerable.
Traditional pile foundations — widely used in cold regions — are facing serious challenges:
Researchers at St. Petersburg Mining University have introduced a novel solution: a dismantlable, modular pile foundation referred to as a dome-plug pile (PDP). It’s a clever upgrade that drastically boosts load capacity while making Arctic construction more flexible, eco-friendly, and cost-effective.
Most piles in permafrost rely heavily on shaft friction — the frozen bond between the pile and the surrounding soil. But what happens when the soil warms or has high salinity?
That bond weakens. A lot.
The team’s innovation is a dome-shaped steel plug installed at the bottom of a steel casing during drilling. This transforms the hollow steel shell into a combined pile-column, allowing it to bear loads both from the side (shaft friction) and from the base (end bearing).
This isn’t just a minor tweak — it's a fundamentally new way to build in the Arctic.
The pile installation uses a well-known technology: Simultaneous casing and drilling (e.g., Symmetrix). This allows drilling through everything — ice-rich soils, frozen rocks, boulders, water-saturated layers — while installing the steel casing at the same time.
Here’s how the modified process works:
A drill string with a pilot bit and a ring bit cuts through frozen and thawed layers while the casing sinks into place.
After reaching the desired depth, the drill string is detached and lifted out.
A steel dome-plug is lowered into the casing and locked in place via a bayonet connection.
This seals the bottom and prepares the pile to work like a column embedded in permafrost.
Because no concrete is used, the pile instantly begins working with the frozen ground, continuing to strengthen as temperatures drop.
The result: A high-capacity, easily dismantlable Arctic-ready foundation element.
Using Plaxis 3D, the researchers ran detailed simulations on six types of frozen soils (clays, loams, sandy loams), both saline and non-saline.
Huge Bearing Capacity Gains
Across all soil types, the dome-plug improves performance dramatically:
| Soil Type | Salinity | Capacity Increase |
|---|---|---|
| Clay | Non-saline | +35% |
| Loam | Non-saline | +41% |
| Sandy Loam | Non-saline | +52% |
| Clay | Saline | +48% |
| Loam | Saline | +61% |
| Sandy Loam | Saline | +63% |
The weaker the soil, the bigger the improvement.
This is crucial — saline permafrost is among the most problematic foundation materials in the Arctic.
Two reasons:
Typical piles in permafrost rely mostly on side friction.
But with the dome-plug…
Up to 45% of the load is transferred through the pile base.
This spreads the load more efficiently, improving stability and reducing settlement.
Simultaneous casing ensures:
The result is a stronger, stiffer load-bearing system.
When the pile hits its limit load, the stress patterns tell the story:
This transformation is the core of the innovation.
One of the biggest engineering and environmental challenges in the Arctic is dismantling. Traditional piles are nearly impossible to remove:
The modular dome-plug pile solves this using thermal debonding.
Required pull-out force: 490–520 kN
Well within the capacity of standard cranes.
No debris. No pollution. Maximum reusability.
This is a game-changer for temporary Arctic installations.
The researchers propose using these piles as the foundation system for modular industrial platforms — built from repeated 6×6 m or 9×9 m blocks.
Benefits:
With the Arctic's environmental sensitivity and increasing industrial activity, this kind of sustainable solution is vital.
Because the pile is hollow, it can double as a thermal stabilization system:
A benefit of this technique is the creation of a strengthened ice–soil matrix near the base of each foundation pile, which is particularly beneficial for stabilizing offshore structures in shallow water.
The research opens multiple paths forward:
Next step: real-world validation on the Yamal Peninsula.
Future work will incorporate:
How should modular grids be arranged for maximum stability?
Transforming piles into smart, thermo-active foundation elements.
Easy extraction = reusable piles = sustainable industrial footprints.
This research shows that modular pile foundations with dome-plugs can revolutionize construction in permafrost regions. They offer:
In a rapidly warming Arctic, engineering solutions must be strong, adaptable, and sustainable — and this innovation checks all three boxes.
Permafrost - Ground that stays frozen for at least two years straight, often containing ice, soil, and rock — common in the Arctic.
Modular Pile Foundation - A foundation made of repeatable, prefabricated pile elements that support modular structures like platforms or buildings.
Pile (Foundation Pile) - A long, slender structural element (often steel or concrete) driven or drilled into the ground to support loads from above.
Dome-Plug (PDP) - A specially shaped steel plug installed at the bottom of a hollow pile to close it off and help transfer loads through the pile tip.
Adfreeze Bond - The "frozen glue" effect where frozen soil sticks tightly to the surface of a pile, helping it carry loads.
Bearing Capacity - The maximum load the ground or a foundation can safely support without failing or sinking too much.
Saline Frozen Soil - Frozen soil that contains salt; it behaves weaker than normal permafrost because salt lowers freezing strength.
End Bearing Resistance - The load carried by the bottom tip of a pile pushing directly onto the soil or rock beneath it.
Shaft Friction (Skin Friction) - The resistance created along the sides of a pile as the frozen ground grips it — a major load-support mechanism in permafrost.
Simultaneous Casing Drilling (Symmetrix) - A drilling method where the steel casing and drill bit advance together, allowing construction through difficult soils, including frozen or saturated layers.
Finite Element Method (FEM) - A numerical modeling technique that breaks a structure or soil mass into tiny elements to simulate stresses, deformations, and performance. - More about this concept in the article "Ultra-Sensitive Soil Moisture Sensor Revolutionized with Photonic Crystals".
Stress–Strain State (SSS) - A snapshot of how a material or foundation is being pushed, pulled, or deformed under applied loads.
Seasonally Thawing Layer (Active Layer) - The top layer of permafrost that freezes in winter and thaws in summer — unstable for foundation support.
Adfreeze Debonding (Thermal Debonding) - The process of thawing the frozen soil around a pile to break the frozen bond so the pile can be removed.
Modular Technological Platform - A large industrial surface built from connected modules (e.g., 6×6 m panels), often used for Arctic drilling and infrastructure.
Trushko, V.L.; Klimov, V.Y.; Baeva, E.K.; Ozhigin, A.Y. Geomechanical Substantiation of the Technology of Constructing Modular Pile Foundations of Technological Platforms in Permafrost Rocks. Geotechnics 2025, 5, 79. https://doi.org/10.3390/geotechnics5040079
From: St. Petersburg Mining University of Empress Catherine II.
