1. REVISION 1
1. Foundations

2. GUIDELINES:
 Where appropriate answers should include sketches.
 Keep sketches simple, mainly sections, elevations and sometimes plans.
Avoid complex 3D illustrations. Include good annotation – lots of notes on
sketches.
 Most questions are divided into a number of subsections. Please ensure that
questions are answered with reference to these individual sections.
 When a question asks for a specific number of examples, e.g. sketch 3
different details, please give that exact number of examples.
 An answer mainly comprising bullet points will be given low marks. Each item
in an answer should include some discussion. 3

3. GUIDELINES:
 The objective of the exam paper is to test students general understanding of
how a complex building is constructed.
 Students are not being examined as construction technologists, but rather as
either clients or consultants that need to be able to communicate intelligently
with construction or architectural experts.
 To this end technical accuracy, although encouraged, is not the essence of
the module.
 General understanding and intelligent reasoning are what is being sought.
 Top quality students, will show a deep theoretical understanding and
practically apply the understanding in writing and with supporting diagrams.
 Students with a basic understanding and communication of their responses in
the subject, will have a mark between 40 and 49 overall. 4

4. Roof coverings (Green Roof) MMC (Off Site Production)
KEY TOPICS: 1. 2. 3. 4. 5. 6. 7.
Foundations
Basements
External Walls
Frame structures
Roof coverings (Green Roof)
MMC (Off Site Production)
Low-carbon construction 7

5. Past Exam Questions
Aug 2010

6. Dec 2010

7. Aug 2011

8. Dec 2011

9. Aug 2012
Aug 2013

10. Dec 2013

13. Answer Guideline
Dec 2009

16. 1- Foundations • Issues surrounding foundation design
• Types of foundation systems
• Recommending a system including sketches •
Understand the role foundations play in either spreading the load of a
building over a wide area or seeking strata deep in the ground, sufficient to
prevent structural failure
More advanced responses will refer to: 1. 2. 3. 4. 5. 6.
Ultimate Bearing Capacity
The likely and permissible degree of settlement
The prevention of relative movement
The level of the water table
The extent of the likely excavation
The area of the roof in view of the consequences of wind uplift forces upon the
foundations
7. The construction process and plant associated with each alternative
8. The likely cost of the available alternative

17. 1- Foundations Foundation Engineering Reports
1. This report is part of foundation design process.
2. All involved in technological aspects of building design must have an
appreciation of foundation engineering reports.
3. The foundation engineering report provides a considered analysis of all of the
data that has been obtained from trial pits, boreholes, site observations, historical
secondary information and laboratory tests. 9

18. 1- Foundations Reports usually includes the following sections: 1. 2.3. 4. 5. 6. 7. 8. 9.
Introduction
General description of site
General geology of area
Description of soil conditions found in boreholes and trial pits
Laboratory test results
Discussion of the results of the investigation in relation to foundation design and
construction
Conclusions/recommendations.
Recommendation of a suitable foundation system based on all of the factual
data. 10

19. A. Shallow Foundations:
Strip Foundations: conventional, wide and deep strip
1. Strap Foundations
2. Pad foundations
3. Raft Foundations: Up stand raft, down stand raft
B. Deep Foundations:
1. Displacement Piles: Driven piles (Casing, precast)
2. Replacement Piles: Bored Piles, CFA Piles
- You should be able to sketch the foundation system clearly.
- Better answers should be able to consider not just the load of the
building but also the type of load e.g. walls or frames. 11

20. 11

21. Sample of Sketches
Pad foundations

22. Raft
Raft foundations are most commonly used to support buildings that are to be placed on soils of low bearing capacity or on soils that have varying levels of compressibility that may lead to difficulties in relation to differential settlement.
Raft foundations can be used to smooth the construction process where the structure is a simple grid of relatively closely spaced columns. In these cases an overall raft avoids disruption and inconveniences that are associated with a relatively large number of excavations for large numbers of independent pad foundations and ground beams.

24. Pile foundations Displacement piles Pre-cast shell piles
Here a temporary pile casing is driven to the required depth, filled with concrete and then the casing
removed. Thus an in-situ pile is cast into the ground. Whatever the type of displacement pile used they are installed by being driven by a percussive force. This has two main disadvantages, noisy installation and production of pressure waves in adjacent subsoil. This last point is of particular importance for service engineers as services buried in the ground, even at some distance from the piles are liable to be damaged.
Piles can be classified by the way they work, end bearing or friction. End bearing piles achieve the required bearing capacity by seeking out strata
below the ground that are capable of sustaining higher loads. With friction piles the load of the building is transferred to the ground through friction between the sides of the pile and the ground through which it passes. In reality piles tend to gain their strength through a combination of friction and end bearing.
Displacement piles
1) Pre-cast shell piles
These are placed by driving a pile or a pile casing into the ground, thus displacing the ground through which it is being driven. A totally pre-formed pile casing is driven into the ground. This pile is composed of short lengths of casing or shells. As the pile casing is driven into the ground, further shells are added until the required depth has been reached. In the example shown the cases are hollow and once positioned are filled with in-situ concrete.
2) In-situ displacement pile
A different type of displacement pile. Here a temporary pile casing is driven to the required depth, filled with concrete and then the casing
removed. Thus an in-situ pile is cast into the ground. Whatever the type of displacement pile used they are installed by being driven by a percussive force. This has two main disadvantages, noisy installation and production of pressure waves in adjacent subsoil. This last point is of particular importance for service engineers as services buried in the ground, even at some distance from the piles are liable to be damaged.

25. Replacement piles
These are placed by boring a hole in the ground and in doing so removing soil. The void is then filled with concrete i.e. the soil is replaced. As the soil is removed it is replaced by concrete which is pumped through the central core of the drill. An interesting alternative of this type of construction is the use of Bentonite slurry, a liquid pumped into the bore hole as the soil is extracted. This liquid supports the sides of the excavation and is in turn replaced by the concrete being placed in the bore hole. Replacement or bored piles are quieter to install, cause no stress waves on the soil but are usually more expensive.
Replacement piles
These are placed by boring a hole in the ground and in doing so removing soil. The void is then filled with concrete i.e. the soil is replaced. As the soil is removed it is replaced by concrete which is pumped through the central core of the drill. An interesting alternative of this type of construction is the use of Bentonite slurry, a liquid pumped into the bore hole as the soil is extracted. This liquid supports the sides of the excavation and is in turn replaced by the concrete being placed in the bore hole. Replacement or bored piles are quieter to install, cause no stress waves on the soil but are usually more expensive.