Eurocode 7 - Elements of Soil Mechanics - page 138

5.2 Introduction to Eurocode 7

5.2.1 Design philosophy

Eurocode 7 - Geotechnical design is published in two parts in the UK by the British Standards Institution as:

● BS EN 1997-1:2004 Part 1: General rules
● BS EN 1997-2:2007 Part 2: Ground investigation and testing

The design philosophy adopted in Eurocode 7 is the same as that adopted in all the Eurocodes and
advocates the use of limit state design to ensure that the serviceability limit states are not exceeded.
Serviceability limit states are those states that, if exceeded, render the structure unsafe even though no
collapse situation is reached, such as excessive deflection, settlement or rotation. In contrast to the tra-
ditional method of the use of lumped factors of safety, the Standard promotes the use of partial factors
of safety and thus reflects a significant shift from traditional UK geotechnical design practice. Where once
the design methods treated material properties and loads in an unmodified state and applied a Factor of
Safety at the end of the design process to allow for the uncertainty in the unmodified values, Eurocode
7 guides the designer to modify each parameter early in the design by use of the partial factor of safety.
This approach sees the representative or characteristic value of the parameters (e.g. loads, soil strength
parameters, etc.) converted to the design value by combining it with the particular partial factor of safety
for that parameter. Worked examples in the following chapters will help the student to follow this approach
to design. Additional explanation on the use of Eurocode 7 is given by Bright and Roberts ( 2004 ), Frank
et al. ( 2004) , C&LG ( 2007) , Bond and Harris (2008) and Simpson ( 2011 ). A thorough review of how
Eurocode 7 has affected geotechnical design is given by Orr ( 2012 ).

5.2.2 Contents of Eurocode 7

The contents of both parts of Eurocode 7 are shown in Fig. 5.3. At first glance it appears that Part 1
covers more subject area and, whilst it arguably does, it is important to appreciate that Part 2 is a signifi-
cantly longer document.
As the titles of the two documents indicate, Part 1 covers the general rules for design whilst Part 2
covers ground investigation practice. The two documents rely on each other for use and it would be very
rare that one part is used in isolation from the other. The use of Part 2 is described in Chapter 6.

Part 1 - General rules Part 2 - Ground investigation and testing

Foreword
1. General
2. Basis of Geotechnical design
3. Geotechnical data
4. Supervision of construction,
monitoring and maintenance
5. Fill, dewatering, ground
improvement and reinforcement
6. Spread foundations
7. Pile foundations
8. Anchorages
9. Retaining structures
10. Hydraulic failure
11. Overall stability
12. Embankments

Foreword
1. General
2. Planning of ground investigation
3. Soil and rock sampling and
groundwater measurements
4. Field tests in soil and rock
5. Laboratory tests on soil and rock
6. Ground investigation report

Annexes A - X

196 pages

Annexes A - J

167 pages

Fig. 5.3 Contents of Eurocode 7 (EN 1997) Parts 1 and 2.