Foundation Systems and Soil Types Quiz

What is the primary purpose of conducting a geotechnical study before starting construction?

• To determine the color of the building

• To establish the load bearing capacity of the soil

• To choose the type of plants for gardening

• To design the landscape

Answer explanation

The primary purpose of conducting a geotechnical study before starting construction is to establish the load bearing capacity of the soil, ensuring the safety and stability of the structure being built.

Which type of rock has a high bearing capacity suitable for foundations?

• Marble

• Sandstone

• Slate

• Obsidian

Answer explanation

Sandstone has a high bearing capacity suitable for foundations due to its strong and durable nature, making it an ideal choice for construction projects.

What is the minimum depth recommended for foundations in high plasticity clays to avoid damage from seasonal moisture variation?

• 750mm

• 1.2m

• 1m

• 900mm

Answer explanation

The correct choice is 1m because a minimum depth of 1 meter is recommended for foundations in high plasticity clays to avoid damage from seasonal moisture variation.

Which foundation system is typically used when the required depth of foundations exceeds 2.5m?

• Strip foundations

• Trenchfill foundations

• Pad foundations

• Raft foundations

Answer explanation

Raft foundations are typically used when the required depth of foundations exceeds 2.5m due to their ability to distribute the load over a larger area, providing stability for the structure.

What is the main reason for using screw pile foundations?

• To increase thermal efficiency

• To reduce construction time

• For aesthetic purposes

• To avoid disturbing tree roots

Answer explanation

Screw pile foundations are used to avoid disturbing tree roots, making them the main reason for their use.

What type of soil is considered very poor for subsoils and may require a reinforced raft foundation?

• Sand

• Peat

• Chalk

• Gravel

Answer explanation

Peat soil is considered very poor for subsoils and may require a reinforced raft foundation due to its high compressibility and low bearing capacity.

What is the typical solution for foundations on sloping sites?

• Stepped foundations

• Deep strip foundations

• Piled foundations

• Raft foundations

Answer explanation

Stepped foundations are the typical solution for foundations on sloping sites as they help to level the structure and distribute the load evenly.

What might affect the choice of foundation system?

• Presence of tree roots

• Color of the soil

• Window sizes

• Type of roofing material

Answer explanation

The presence of tree roots can affect the choice of foundation system as they can cause soil movement and instability, impacting the foundation's integrity.

What is the purpose of lining trenches with compressible material in clay soils?

• To attract wildlife

• To protect foundations from expansion damage

• To improve drainage

• To reduce concrete usage

Answer explanation

Lining trenches with compressible material in clay soils is done to protect foundations from expansion damage, not for attracting wildlife, improving drainage, or reducing concrete usage.

Why might a soil survey not be a prerequisite for starting construction?

• All construction requires no survey

• Soil types don't affect foundation choices

• It's too expensive

• Local expertise or designer knowledge may suffice

Answer explanation

Local expertise or designer knowledge may suffice because they can assess the soil conditions and recommend suitable foundation options without a formal survey.