science

Ground freezing

Ground freezing is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Ground freezing rather than just read about it. In short: Artificial ground freezing is a construction technique used in circumstances where soil needs to be stabilized so it will not collapse next to excavations, or to prevent contaminants spilled into soil from being leached away. Artificial ground freezing was used for the first time in 1862 in Swansea, South Wales, UK by Siebe Gorman & Co.

Key takeaways

Ground freezing belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ground freezing to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ground freezing from memory before moving on to harder problems.

Reference excerpt

Artificial ground freezing is a construction technique used in circumstances where soil needs to be stabilized so it will not collapse next to excavations, or to prevent contaminants spilled into soil from being leached away. Artificial ground freezing was used for the first time in 1862 in Swansea, South Wales, UK by Siebe Gorman & Co. The system was applied for a coal mine shaft sinking. Pipes are run through the soil to be frozen, and then refrigerants are run through the pipes, freezing the soil.

Design Some artificial ground freezing projects use common salt brine as the refrigerant, but other projects benefit from using more exotic refrigerants, like liquid nitrogen or solid carbon dioxide ('dry ice').

Examples Soil contaminated with radioactive elements that leaked from Japan's Fukushima Daiichi nuclear power plant was contained through artificial ground freezing. A project in Boston known as the Big Dig used artificial ground freezing during some of its tunneling, to allow its wide tunnels to be built under or through soil that supported existing infrastructure that would have been difficult or expensive to support using more traditional excavation methods. In northern Canada and arctic Alaska, passive pipe systems are used that do not require any external power to keep the ground frozen. These systems use in-ground evaporators and above-ground radiators filled with liquid refrigerant. When ambient temperatures fall below ground temperatures, the liquid vapor starts condensing in the radiator, reducing the pressure in the system causing the liquid in the evaporator to boil and evaporate. This process results in heat transfer from the ground to the air and keeps the ground in a permanent frozen state. Hani and Evirgen (2023) introduced a new method for sampling granular soils without disturbing their natural state; they suggest using artificial artificial ground freezing, a ground enhancement technique, as an on-site option for deep excavation applications.

See also Pykrete, a composite building material which utilizes similar properties in frozen sawdust, Hani and Evirgen investigated the mechanical and microstructural properties of an artificially frozen sawdust-ice mixture (pykrete) and its usability as a retaining structure. In addition, they developed an uncoupled thermo-hydro-mechanical approach to simulate a pykrete diaphragm wall for numerical analysis using finite element methods.

References

Illustrations

Worked examples

Example 1 — a first encounter with Ground freezing

Start with the simplest possible case. Write down what Ground freezing claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ground freezing before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ground freezing ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ground freezing

In research: Ground freezing appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ground freezing in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ground freezing is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ground freezing, so understanding it makes those chapters shorter.
In everyday life: Look for Ground freezing outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Ground freezing in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ground freezing means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ground freezing out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ground freezing in simple terms?

Why does Ground freezing matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ground freezing?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ground freezing.