Construction Technology & Environmental Services

Question 1

What is sub-structure?

Answer 1

All elements of the work that are undertaken below the damp proof cause that provides the basis for the superstructure to be constructed upon.

Question 2

What is the external envelope?

Answer 2

The materials and components that form the external shell or enclosure of a building. These may be load or non-load bearing.

Question 3

What are the Building Regulations?

Answer 3

Statutory instruments that set out the minimum performance standards for the design and construction of buildings.
They are supported by the Approved Documents and other codes of practice.

Question 4

What are the Approved Documents?

Answer 4

A - Structure
B - Fire
C - Site Preparation and Damp Proofing
D - Toxic Substances
E - Sound Proofing
F - Ventilation
G - Hygiene
H - Drainage and waste Disposal
J - Heating Appliances
K - Protection from Falling, Collision, and Impact
L - Conservation of Fuel and Power
M - Disabled Access and Facilities

Question 5

What are British Standards?

Answer 5

Publications issued by the British Standards Institution, prefixed BS.
They give recommended minimum standards for materials, components, design and construction practices.

Question 6

What are International Standards?

Answer 6

Publications issued by the International Organisation for Standardization - Prefix ISO.
They are compatible with and complement the British Standards.

Question 7

What is Superstructure?

Answer 7

• All internal and external works items above the DPC. This is made up of:
• External Walls
• Stairs
• Roof
• Structural Walls
• Suspended Ceilings
• Raised Floors

Question 8

What are the typical components of site investigations?

Answer 8

Their objective is to collect and record data to help with the design and construction process. This should include matters in relation to the site that may impact the development, for example:
- Boundary Hedges & Fencing
- Existing Trees
- Size, Depth & Location of Services
- Existing Buildings
- Ground water Conditions
- Soil Investigations
- Trial Pit Information

Question 9

What is the purpose of soil investigations?

Answer 9

Their purpose is to determine the suitability of the site for the proposed works and determine adequate and economic foundation design.
The investigation should determine the potential difficulties associated with the ground conditions and assist with identifying a suitable foundation solution.

Question 10

What are the main site considerations?

Answer 10

• Access
• Storage
• Accommodation
• Temporary Services
• Plant
• Fencing & Hoarding
• Health & Safety Risks

Question 11

What is a retained facade?

Answer 11

The facade of a building which is retained whilst the entirety of the building the wall (facade) is demolished.
Allowances need to be made for a temporary support structure, and also cleaning and restoration works to the retained facade.
Retained facades are often required as a result of listed building consents.

Question 12

What are temporary works?

Answer 12

Temporary works do not usually appear on construction drawings, but may be required depending on the construction methodology being used.
Temporary works may also be required as a result of health & safety requirements to ensure a safe method of construction, for example temporary propping.

Question 13

What is a tower crane and what are the considerations during its erection and operation?

Answer 13

• A tower crane is a tall crane used for lifting objects into high places.
• The boom allows a longer reach with 360 degrees 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.

Question 14

What is a scaffold?

Answer 14

• Scaffold is a temporary working platform erected around the perimeter of a building or structure to provide a safe working place at a convenient height.
• Scaffold is usually required for work above 1.5m above ground level.

Question 15

What is shoring?

Answer 15

Shoring is a form of temporary support given to existing buildings. Its purpose is to provide a precaution against damage or injury due to collapse of the structure.

Question 16

What are the main components of concrete?

Answer 16

Cement
Aggregate
Water

Question 17

What is a borehole?

Answer 17

• A borehole can be used for soil investigation or for geothermal heating solutions.
• Boreholes are the most suitable method of soil investigation when foundations are over 3m deep.
• Geothermal boreholes are permanent boreholes that use the earths natural heat to raise the temperature of circulated water.
• This is a closed system and can be used to heat the building above which is a sustainable technology.

Question 18

What are piles?

Answer 18

• A series of columns constructed or inserted into the ground to transfer the load of the structure to firm strata.
• They are used where no suitable foundations conditions are present near ground level, or if there is a high water table.

Question 19

What are the different types of piles?

Answer 19

1 - Sheet Piles.
- A deep trench is excavated and concrete is poured in-situ.
- The piles can be used to firm basement walls or act as retaining walls.
2 - Seacant Piles.
- Interlocking piles (male and female) are bored to provide a combination of foundations and basement walls.
- They support in providing a waterproof structure and are often seen when a top down construction method is used
3 - Bored Piles
- An auger is used to excavate the soil and then concrete is poured in when complete.
4 - Pre-Cast Piles
- Piles are hammered into the ground. This is not often favored due to the noise levels associated with installation and the lack of flexibility in terms of depth required.
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Question 20

What are the different ways that the piles transfer their load to the surrounding ground?

Answer 20

1 - End-Bearing. Transfer load through low bearing capacity soil to a firm stratum such as rock or very dense sand.
2 - Friction. Bear on frictional resistance between their outer surface and the soil in contact.
3 - Settlement Reducing Piles. Usually incorporated beneath the central part of a raft foundation in order to reduce differential settlement to an acceptable level.
4 - Tension Piles. Resist uplifting forces that might otherwise force the structure to become extracted from the ground due to uplifting forces such as hydrostatic pressure, seismic activity or overturning movement.

Question 21

What is the difference between bored vs pre-cast piles?

Answer 21

• Bored piles are defined 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 vibration is limited.
• Pre-Cast concrete piles are generally used where soft soil deposits overlie firmer strata. These piles are usually driven using a drop or single action hammer. Issues can arise due to the noise levels associated with the installation method of pre-cast piles.