Site investigations are a prerequisit for the planning of all major geotechnical projects. The methods applied during this exploratory stage cover nearly all disciplines of geosciences like Geology, Hydrology, Geomechanics and, last not least Geodesy and Geophysics. The demand for high quality information on the one hand and limited budgets and tight time schedules on the other hand make it necessary to develop efficient strategies in geotechnical exploration. Special aspects of geotechnical exploration strategies are the efficient combination of exploration methods, the optimization of cost and time used, the mutual exchange of information and feedback, and the joint multidisciplinary interpretation.

For developing and improving exploration strategies in the fields of geotechniques the geodetic community should be able to give valuable contributions not only within the classical limits of it's discipline, but also in combining geophysical and geodetic methods and in supplying data platforms on a decision level. To stimulate this development a plenary session at the Symposium on Geodesy for Geotechnical and Structural Engineering, Eisenstadt, Austria, April 20-22, 1998, was organized where the following invited papers were presented.

Toni R. SCHNEIDER (Consulting Geologists, CH-8713 Uerikon, Switzerland), Development of the Geological Investigations in a Geotechnical Project

Abstract: The development of the geotechnical investigations in a geotechnical project is demonstrated. The sequence of the different phases is described according to the actual legislation in Switzerland, more or less independent of the type of the project, e.g. tunnels, bridges, roads, railways, dams. It is shown which state of knowledge has to be reached on each step and the main types of investigation methods are mentioned. Special consideration is given to the geodesic contribution in each phase.

Harald GRANSER (ÖMV AG, Vienna, Austria), Exploration Strategy for Hydrocarbons

Abstract: A short description of the exploration process for oil and gas is given. Geophysical and geological methods are discussed with main emphasis on seismic processing and interpretation as the most important tool of the explorationist. Drilling and logging of a well and the follow-up procedures in case of a discover which eventually may lead to a field development are briefly summarized.

Johannes KLEBERGER (Geoconsult ZT GmbH, Salzburg, Austria) Methodology of Engineering Geological Exploration

Abstract: Reliable knowledge about ground conditions is vital for any civil engineering project on the ground or underground. Ground conditions strongly influence on where to locate, how to design and built the project as well as on cost, safety and lifetime of the structure. Independently of ground conditions and the kind of project site investigation procedures should follow a basic approach. The paper shows principles of a conceptual methodology for engineering geological exploration and demonstrates the range of investigation tools and disciplines involved.

Manfred KÖHLER (Brenner Eisenbahn GmbH, Innsbruck, Austria), Munich-Verona Rail Link -Project Management and Investigation Programme of the Brenner Eisenbahn GmbH (BEG)

Abstract: On 1 January 1996 the Brenner Eisenbahn GMbH initiated project development measures for the Wörgl-Baumkirchen section in the Austrian Lower Inn Valley as the first selection of the Brenner rail link. A full investigation programme was executed in preparation for the environmental impact assessment. Following analysis of the results, improvements were made to the projected line of the route, especially in the Gnadenwald Terrace area.

These four papers gave an excellent overview of the classical, more sequential approach to geotechnical exploration, the dominating influence of geophysical exploration techniques in the field of hydrocarbon exploration, the demand for a wide interdisciplinary, not only geoscientific cooperation and finally the approach chosen during the planning of an important new railway line. The following four other papers were presentented in a special session giving examples of activities going beyond the limits of classical geodesy.

Heimo SCHARLER, Gerhard STOLITZKA (Institute of Geodesy, Remote Sensing and Land Information, University of Agricultural Sciences, Vienna, Austria), An interactive Tool for the Analysis and Interpretation of Geodetic Deformation Measurements in Tunneling

Abstract: In most cases common data preparation techniques for the interpretation of geodetic deformation data use onedimensional spline interpolation to model the deformation process. The paper proposes the collocation method to generalize this approach and to enlarge the possibilities, to make the evaluation of various differential and integral functionals applied on the mesured deformation field possible. The basic steps of the mathematical formulation,

examples for the evaluation of nonlinear functionals, the derivation of the corresponding covariance functions and the implementation into a graphical user interface is presented.

O. ALTAN et. al. (Istanbul Technical University, Turkey), Photogrammetry and GIS for the Acquisition, Documentation and Analysis of Earthquake Damages

Abstract: Earlier earthquakes revealed problems in the processes of documenting and analysing the building damage that occurred due to earthquake disasters which demanded time and man power. The aim of this paper is therefore to make a contribution to the improvement of this situation. It shall be reached by the combined use of a photogrammetric acquisition method and a Geographic Information System (GIS).

G. OTEPKA (Ingenieurgemenischaft Vermessung, Imst, Austria), Methods and Possibilities for Data-Acquisition, Data-Visualisation and Data Mangement

Abstract: The acquisition, visualisation and management of data is important for the most engineering projects. Surveyors and photogrammetrists are educated and trained to carry out parts of the needed measurements, computations and presentations within such projects. Some methods and possibilities for data-acquisition, visualisation and mangement are discused. Applications of these possibilities will be presented.

E. MATTANOVICH (ARGE Raum-Umwelt GesmbH, Vienna, Austria), For joint processing of metric and thematically valuating data

Members of the Working Group WG5:

Schneider Toni R.

Geologische Expertisen

Rütihofstr. 53

CH-8713 Uerikon

Switzerland

Tel.: 0041 1 926 3046

Fax.: 0041 1 926 3779

Granser Harald

OMV

Gerasdorferstr. 151

A-1210 Wien

Austria

harald.granser@omv.co.at

Kleberger Johannes

Geoconsult ZT GmbH

Sterneckstr. 52

A-5020 Salzburg

Austria

jkl@gcs.co.at

Köhler Manfred

Brenner-Eisenbahn-Gesellschaft

Neuhauserstr. 7

6020 Innsbruck

Austria

Tel.: 0512 5309

Fax: 0512 5309 10

Altan Orhan

ITU Insaat Fakültesi

Ayazaga Kampusü

80626 Istanbul

Turkey

oaltan@srv.ins.itu.edu.tr

Fritsch Dieter

Universität Stuttgart

Geschwister-Scholl-Str. 24

D-79174 Stuttgart

Germany

Dieter.Fritsch@ifp.uni-stuttgart.de

Scharler Heimo

Dipl.-Ing. Hanns H. Schubert

Ing.kons. für Vermessungswesen

Kremser Landstr. 2

A-3100 St. Pölten

Austria

GeoInfo@SchuGeo.co.at

Stolitzka Gerhard

BOKU Wien

Peter-Jordan-Str. 82

A-1190 Wien

Austria

scharler@edv1.boku.ac.at

Otepka Gottfried

Ingenieurgemeinschaft Verm.

AVT-ZT GesmbH

Eichenweg 42

A-6460 Imst

Austria

otepka@imst.netwing.at

Mattanovic Ernst

ARGE Raum Umwelt GesmbH

Theobaldg. 16/4

A-1060 Wien

Austria