What is substructure?
All structure below the superstructure i.e. all structure below ground level including the ground floor bed
What is Superstructure?
All internal and external structure above the substructure
Made up of primary (ext walls, stairs, roof, structural walls) and secondary (suspended ceilings / raised floors, balustrades, doors) elements and finishes (tiles, paint, stair nosings)
What is the External Envelope?
The materials and components that form the external shell or enclosure of a building
May be load or non-load bearing
What are the Building Regulations?
What are the approved documents?
What are British Standards?
What are international standards?
Prepared by the International Organisation for Standardisation – prefixed ISO
Compatible with and complement BS’s
Example - ISO9000 is quality
What are the typical components of site investigations
tower crane is a tall crane used for lifting objects into high places. The boom allows a longer reach with 360 access. A longer boom reduces the payload capability.
You would usually use a smaller crane to erect a tower crane
Weather conditions could prevent it from working, in particular high, strong winds.
Temporary working platform erected around the perimeter of a building or structure to provide a safe working place at a convenient height
Usually required for work above 1.5m above ground
- Purpose is to provide a precaution against damage or injury for collapse of structure
Sheet piles – a deep trench is excavated and concrete is poured in situ. The piles can be used to form basement walls or act as retaining walls.
Secant piles – interlocking piles (male and female, often different diameters and hardness) are bored to provide a combination of foundations and basement walls. They go someway in providing a waterproof structure. Secant piles are often seen when a top down construction method is used.
Bored Piles – an auger is used to excavate the soil and then concrete is poured in once complete. A variation to this is CFA (Continuous Flight Augered) where the piles are bored, Bentonite slurry is pumped in to stop the core collapsing and then concrete (which is denser than Bentonite) is poured in. Bentonite is environmentally harmful and is therefore not often used in the 21st century.
Pre-cast piles – pre-cast piles are brought to site and hammered into the ground. Not often favoured due to the high noise levels associated with installation and the lack of flexibility in terms of depth required.
Bored piles - when the process for removing the spoil to form the hole for the pile is carried out by a boring technique. They are used primarily in cohesive subsoils for the formation of friction piles and when forming pile foundations close to existing buildings where the allowable amount of noise and/or vibration is limited.
Pre-cast Concrete piles - used where soft soil deposits overlie firmer strata. These piles are usually driven using a drop or single action hammer.