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:
❌ Reduced bearing capacity as permafrost warms
❌ High construction difficulty in frozen soils with rock inclusions
❌ “Wet processes” like concrete pouring become impossible in extreme cold
❌ No realistic way to dismantle piles after project completion, leaving steel and concrete behind
❌ Environmental risks in fragile northern ecosystems
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:
🏗️ Fast assembly
❄️ Year-round construction
♻️ Complete reversibility
💰 Lower cost than artificial islands (up to 5× cheaper)
🌱 Minimal disturbance to fragile Arctic landscapes
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:
💪 Higher bearing capacity
❄️ Better performance in thawing and saline soils
🏗️ Fast, all-season installation
♻️ Full dismantling with minimal environmental impact
🧊 Potential for thermal stabilization
📦 Perfect fit for modular industrial platforms
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. - More about this concept in the article "🏗️ Revolutionizing Shear Wall Reinforcement: A Game-Changer for Structural Engineering".
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.
Source: 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.
