PREDICTIONS FROM THE INITIAL ENGINEERING GEOLOGY ENVIRONMENT MODELS

In summary: the global Tectonic models provides the setting for the other two groups of models. The site scale Geomorphological and Geological models have annotations and key descriptions to form the basis for the check lists, since it is these models which provide the initial basic conceptual picture of the local potential conditions. Of course, an understanding of the actual geology/geomorphology of the site must come from the subsequent ground investigation.

We also repeat, we consider it essential that an engineering geologist/geomorphologist of experience be involved in important projects. It is his/her training and experience that are needed to interpret and develop the engineering geology history and to input to the planning and the investigation design.

At the desk study stage: the relationship of the initial models for identifying and building the site check list is:

Identify Relevant Global Tectonic Model(s)

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Identify Relevant Initial Site Scale

Geological + Geomorphological Model(s)

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Preliminary Site Check List(s)

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Preliminary Site Engineering Geology Environment Model

When the preliminary site engineering geology environment model has been developed, it is used for overall planning and for the design of the preliminary ground investigation or the full ground investigation, should there be no preliminary investigation stage.

At the ground investigation stage(s): a well designed ground investigation should now progressively identify site conditions, answer check list questions and give information to build the site real model(s). It is not the intention here to elaborate on the development of the specific site geological/geotechnical model(s) and the conduct of the ground investigations - guidance is given in numerous publications, but it is worth emphasising that the site check list should continue to be systematically evaluated and developed, using geological/ geomorphological judgement and the findings from the investigation.

It is also necessary to emphasise that the investigation should not consist solely of boreholes. Adequate engineering geology/geomorphology mapping should be carried out or be in place early in the investigations, and pits and other high return ground observation techniques should figure largely in the investigation. Engineering geological/geomorphological interpretation of the situation must be continuous and early observation and deductions continuously reviewed, objectives defined and questions asked (see for example Stapledon, 1983 and 1996). This process must continue into construction and the service life of the project.