Foundations and Substructures Flashcards
(20 cards)
What is the primary function of foundations?
To safely transfer building loads to the ground.
What is the difference between shallow and deep foundations?
Shallow foundations are near the surface (e.g. strip footings), deep foundations transfer loads deeper via piles.
Name two types of shallow foundations.
Strip footings and raft foundations.
What is a pile foundation?
Long slender columns driven or bored into the ground to transfer loads to deeper, stable soil.
When are raft foundations typically used?
On soft or unstable soils to distribute loads across a large area.
What is CFA piling?
Continuous Flight Auger – concrete is pumped through a hollow auger as it’s withdrawn to form piles with minimal vibration.
What is a pile cap?
A thick concrete mat that connects the tops of piles and transfers loads from the superstructure.
What is blinding?
A thin layer of concrete poured over excavation to provide a clean base for reinforcement.
What is the purpose of reinforcement in foundations?
To resist tensile forces and prevent cracking.
What are secant pile walls used for?
Forming retaining walls or waterproof basements using overlapping concrete piles.
What is a capping beam?
A reinforced concrete beam that links pile heads or contiguous piles for structural integrity.
Why is a soil investigation important before designing foundations?
To assess ground bearing capacity, settlement risk, and soil composition.
What is meant by differential settlement?
Uneven foundation movement that can cause structural damage.
What is dewatering and why is it necessary?
The removal of groundwater to allow safe and dry excavation.
What is the purpose of a basement retaining wall?
To resist soil pressure and provide watertight support to basement levels.
What is pile cropping?
Trimming concrete piles to the required level after installation.
When is underpinning required?
To strengthen or stabilize existing foundations, especially during nearby excavation.
What is a ground beam?
A reinforced concrete element connecting foundations, distributing loads between them.
What is the main risk during basement excavation?
Collapse or water ingress due to poor support or drainage.
Why is waterproofing crucial in substructures?
To protect the building from water damage and structural degradation.
