1841
Technical Committee 205 /
Comité technique 205
project due to mistakes or inefficiencies associated with this
misguided approach.
It is here suggested that, without neglecting the value that
project management and commercial specialists add to the
delivery process, it is extremely important that high level
decision-making incorporates sufficient input from technical
experts. The subject deserves a richer and broader discussion
than what is possible in this conference paper. The author
agrees with Muir Wood (2004) on the detrimental role of
discontinuity – sometimes deliberately enforced – between the
functions of design and construction, and of the fragmentation
of responsibility. Without reasonable continuity and unity a
project is unlikely to meet satisfactory ethical standards with
respect to impact on the society and the environment. Even the
success in strictly engineering terms is endangered. In Muir
Wood’s words a successful engineering project comprises
a
Client whose requirements have been understood and fulfilled;
a Contractor who has been adequately reimbursed for a job
well done; an Engineer who has fully understood the Client’s
need and has applied competence and creativity to a well-
engineered project.
The final sign of success is
the rarity of
unresolved dispute and litigation
. It is worth highlighting how
this last point is largely dependent on the trustworthiness of the
Engineer and all other parties. It is also strongly linked to the
Engineers’ reputation (see Section 2.2) and their conduct
(Section 2.1).
A useful concept to inform the current and future discussion
on successful forms of contract and procurement strategies is
the Intelligent Market discussed by Muir Wood and Duffy
(1991). This approach focuses on a holistic approach which
avoids fragmentation and neglect of synergy, in summary taking
generated value, not cost, as the main criterion for decision
making.
4 SPECIFICITY OF GEOTECHNICS
4.1 Uncertainty and judgement
In geotechnical engineering uncertainties are typically larger
than in other branches of civil engineering (structural
engineering in particular). The analysis of geotechnical systems
and the decision making associated with planning, designing
and maintaining them often contains an unavoidable and
significant component of engineering judgement. This can (and,
when possible at all, should) be based on and informed by the
existing literature, which condenses valuable and selected
experience from others. However, in many circumstances
individuals or teams of engineers have to introduce a
considerable amount of subjective opinions in to the design
process in order to achieve practical and usable solutions.
This consideration reveals how ethics, intended as good
decision-making under uncertainty, bears particular relevance to
the geotechnical discipline. The consequences of large
uncertainty and reliance on judgement are numerous. On the
one hand, geotechnical engineers willing to deliberately distort
design outcomes for their own interests or for the interest of
their direct employer can easily do so, when dealing with a
client who is not familiar with ground behaviour and
geotechnical works, by cherry-picking the most convenient
results within the often large uncertainty band associated with
different interpretations of site data and the selection of
different models. On the other hand, the honest and scrupulous
engineer in a consulting company may meet with resistance
externally – with clients – and internally – with project
managers and colleagues from other disciplines – when
correctly trying to incorporate in to the design in a transparent
way large levels of uncertainty which others may wish to
ignore.
In this context helpful ethical behaviours from the
geotechnical engineer include building trust by avoiding over-
conservatism and by communicating risk accurately, also
highlighting which assumptions and hypotheses are judgement
based. At the same time experienced geotechnical engineers
need to hold their ground when unreasonably pressed to under-
represent and under-communicate uncertainty. The author
believes that in a discipline so closely associated with
quantification of judgement a basic knowledge of the principles
of cognitive psychology which are relevant to this task
(Kahneman
et al
. 1982) should be more widespread.
Considering that large uncertainty on the performance of
even very common geotechnical structures is not unusual, it is
here suggested that national and international professional
bodies and institutions should start recording statistical data on
the key performance indicators for large numbers of structures.
4.2 New challenges
The constant evolution of geotechnics, and of the perception
that mankind has of its own role and position on the planet,
bring to light new ethical issues which should be incorporated
in to the daily activity of geotechnical engineers. For example,
the necessity of limiting greenhouse gasses emissions and of
containing, as much as possible, the consumption of energy and
other finite resources have never been so clear. These concepts
need to become part of the basic consideration a geotechnical
designer goes through when selecting and developing technical
solutions (see for example Inui
et al.
2011). Most importantly,
the tendency to regard a large uncertainty in the performance of
structures as tolerable and the inclination to deal with it by
overdesigning, which implies producing a safer but potentially
very wasteful structure, is becoming increasingly unacceptable.
In fact such an approach cannot continue in the face of the new
perception that the current generation must preserve the health
of the environment and avoid resources depletion as much as
reasonably practicable. Avoiding wasteful design is becoming
an ethical imperative which cannot be achieved without credible
understanding,
accurate
management
and
effective
communication of uncertainties.
One more challenge currently presented to geotechnical
engineers is the adoption of new, more complex and potentially
more powerful, design codes. An obvious example is the suite
of Eurocodes adopted by the European Union and other
countries in recent years. The complexity of these codes
requires particular attention to the communication between
specialists of different disciplines if mistakes are to be avoided.
Currently, in most consulting companies, the design of
geotechnical structures (for example retaining walls) is jointly
carried out by a geotechnical specialist and a structural
specialist. The former verifies the geotechnical stability and
provides structural actions from geotechnical considerations (for
instance a soil-structure interaction analysis), whilst the latter
provides the loading combinations to be studied and checks the
structural safety on the basis of the geotechnical analysis results.
This interaction, often iterative in its nature, requires particular
attention to the communication across discipline boundaries.
For example geotechnical engineers designing a structure
according to Eurocode 7 – EN 1997 – will have to check and
double check that they are fully understanding and using
correctly the numerous load combinations that they receive
from their structural colleagues. Similarly, when providing
results in terms of structural actions, the geotechnical engineers
need to carefully communicate to their structural colleagues the
relevant explanations and clarifications about how the
geotechnical calculations have been developed. A typically
delicate situation is, for example, the incorporation of partial
factors for the STR/GEO ultimate limit states (ULS) in soil-
structure interaction analysis (for instance with the finite
element method). In this specific circumstance the ULS partial
factors from EN 1997-1 need to be rearranged (see for example
Bond & Harris 2008) in a way which may be confusing. A
discussion of such aspects and an additional effort to ensure the
