Environmental Engineering Reference
In-Depth Information
The consequences of a poorly planned or inadequately funded feasibility stage investi-
gation can be:
-
Adoption of the less satisfactory of two alternative sites;
-
Adoption of a site which later proves to be non-feasible or for which large cost over-
runs occur to address unforseen conditions (for examples of such sites see Table 3.4);
-
Abandonment of a site (or possibly a whole project) which would have been proven
feasible, by well conceived (but expensive) studies.
The authors consider that the 'observational method' as adopted by Terzaghi & Leps
(1958) at Vermilion Dam, should not be used as a means of overcoming funding difficul-
ties during the feasibility and design stages of dam projects. They agree with the practice
of excavating part or all of the dam foundations during the design stage, or prior to
awarding the main construction contract (Hunter, 1980), but believe that this should be
done only when all questions relating to feasibility of the project have been adequately
answered.
4.7
THE SITE INVESTIGATION TEAM
The following seven attributes for success in site investigations for dams, put forward by
Stapledon (1983), suggest that a team approach is necessary, especially for large dam projects:
1. Knowledge of precedents;
2. Knowledge of geology;
3. Knowledge of soil and rock mechanics;
4. Knowledge of geotechnical, dam, and civil engineering design;
5. Knowledge of civil engineering and dams construction;
6. Knowledge of direct and indirect exploratory methods;
7. Above average application.
It should be clear from Section 4.1 to 4.4, that Attributes 1 to 5 are necessary for under-
standing, defining and answering the geotechnical questions associated with dams.
Attribute 6 refers to direct subsurface exploratory methods (e.g. pits, boreholes) and
indirect methods (e.g. geophysical transversing). Knowledge of the application and limi-
tations of methods such as these is necessary if the questions posed are to be answered
effectively and economically.
The authors consider that these six attributes are necessary for successful site investiga-
tions for dams. They also consider that these attributes can be provided most effectively
by a team including engineering geologists and engineers. It is important that all team
members have enough 'general' knowledge in all areas to be able to communicate effec-
tively with one another and with engineers involved with the design, construction and
operation of dams. As well as having this broad knowledge of the industry, it is desirable
that they have Attribute 7, 'above average application' as defined by Stapledon (1983)
“
…
ability to get things done; this involves effective cooperation with others, enthusiasm
and drive and the ability to make decisions in the field.”
