Pile Design and Construction Practice, Fifth edition

The contractor’s guarantee is usually limited to that of the load/settlement characteristics
of a single pile and for soundness of workmanship, but his responsibilities regarding effects
due to installation extend to the complete structure and to any nearby existing buildings or
services. For example, if a building were to suffer damage due to the settlement of a group
of piles and the settlement were due to the consolidation of a layer of weak compressible soil
beneath the zone of disturbance caused by pile driving (Figure 1.3), the contractor could
reasonably decline to accept responsibility. The engineer should have considered this in his
overall design and specified a minimum pile length to take account of this compressible
layer. On the other hand, a contractor is regarded as responsible for any damage to
surrounding structures caused by vibrations or ground heave when driving a group of piles,
or by any loss of ground when drilling for groups of bored and cast-in-place piles.
Because of the great importance of installation effects on pile behaviour, the various types
of pile available and their methods of installation are first described in Chapters 2 and 3,
before going on to discuss the various methods of calculating allowable loads on single piles
and groups of piles in Chapters 4–6.

1.7 References

1.1RANDOLPH, M. F. Science and empiricism in pile foundation design, Geotechnique, Vol. 53, No. 10,
2003, pp. 847–75.
1.2BSEN 1997-1:2004 Eurocode 7: Geotechnical Design, Part 1 General Rules, British Standards
Institution, London.
1.3BSEN 1992-1:2004 Eurocode 2: Design of Concrete Structures, Part 1-1 General Rules and Rules
for Buildings, British Standards Institution, London.
1.4BSEN 1990 Eurocode 0: Basis of Structural Design, British Standards Institution, London.
1.5FRANK, R., BAUDIN, C., DRISCOLL, R., KAVVADAS, M., KREBBS OVESEN, N., ORR, T., and SCHUPPENER, B.
Designers’Guide to EN 1997-1 Eurocode 7: Geotechnical Design– General Rules, Thomas
Telford, London, 2004.

General principles and practices 9

Load transfer

Weak compressible soil

Hard incompressible

soil

Soft compressible

soil

Soil disturbedby pile driving

Figure 1.3Pile group terminating in hard incompressible soil layer underlain by weak compressible soil.