6th EAGE/EEGS Meeting

The history of soviet military areas in the Central and Eastem Europe started in 50 ties and 60 ties of this century. The military techniques (heavy lorries, tanks, fighters) needed a lot of fuel and high volume underground storage tanks (UST) has been put into the ground without any insulating layer. The leakage a) of USTs - getting rusty during the long period till 90 ties, b) of tubes and pipes transporting the fuel from tank-wagons to UST's in the area of railway terminals, c) caused by irresponsible handling with fuel by soldiers of the soviet army polluted the soil, the vadose zone, the saturated zone and consequently the ground water. The spills can be characterised as long lasting over many years creating the free product layer thick first decimetres to first meters on the groundwater table. Such a situation has been found at the beginning of 90 ties, when the areas has been abandoned in all countries of the former Warsaw Pact. Below, our experience with geophysical prospecting of these sites is discussed.

The investigation of potential underground deposits for toxic and radioactive waste in salt rock is achallenge for geophysical exploration methods, because the conditions for geophysical measurements are rather poor and the direct geological exploration with bore holes has to be minimized.

The detection of cavities in the subsurface is important for both engineering geological site investigations (sinkholes) and tourism (large caves). Under favorable conditions this problem can be solved using geoelectric methods (Chan et al., 1996). However, in reality, in many cases geoelectric results are biased by the existence of false anomalies caused by lateral inhomogeneities in the geoelectric cross-section.

Sangemil spa area is located 16 km south of Viseu, Central Portugal, near the Däo river. The productive wells, F1 and F2 are located in the alluvial plain of the river and have been threatened by the river floods (Fig. 1). In order to locate new production wells, out of the alluvial plain and close to the spa unit the surrounding geological structure was surveyed. The proposed structural model claimed for a geophysical survey with two profiles P1 and P2 (Fig. 1) using dipole-dipole array. Taking into account the results obtained, three new wells HDN1, HDN2 and HDN3 (Fig. 1), have been drilled (85 to 112m deep). The field measurements of conductivity, temperature, pH and yield are discussed in conjunction with the geophysical results.

The objective of investigation was the determination of representative hydraulic state functions (capillary pressure vs. water saturation curves) on large sand and sandstone samples using a combination of traditional hydraulic and new geophysical techniques. Of practical interest are residual water saturation, residual air saturation and the hysteresis of imbibition and drainage processes (see fig 1). These parameters may be used for validation of multiphase flow processes as well as the estimation of effective porosities and other geohydraulic quantities. It was shown that petrophysical and geophysical methods contribute to the reduction of risk and uncertainties in forecast of groundwater related processes in former mining areas.

Geophysical methods are increasingly used for the solution of geotechnical problems. For a road construction in an alpine valley geotechnical problems are determined by strong deformations and landslides.

Principal tracks of the Moscow Railway were built in 1860-1870. Before WWI first serious reconstruction took place, when the second track was built. During WWI and WWII west-bound routes suffered severely and the traces of the urgent repairings are still obvious in the embankment. The embankments are built mainly in complicated geological conditions in marshy areas. Under constant vibration and dynamic loading irreversible deformations take place resulting in gradual ground displacements.

GEOTEC Sh.p.k. have been performed geological-engineering and geophysical observations for in-situ investigate the geology and geotechnical conditions of the dam area of the Vlahna reservoir at the Hasi district, in northeastern part of Albania. This is a very important irrigation work, because it will be constructed in one of the driest areas in Albania. The particularity of this investigation consists that has performed in area with complicated geology of the ophiolitic belt of Albanides, and in mountain region.

The Sanctuary of Monterosse has been re-located on the top of a clay hill close to the Terricciola (Pisa) after the big earthquake, which destroyed its Romanesque aspect. Now that Sanctuary is collapsing mainly because of the general hydro-geological evidences and the periodical behaviour of the water-table resting on the clay bedrock quite inclined downhill. The aim of this paper is to propose a synthetic summary of the activities directed to sauveguard and protect such a singular specimen of religious architecture in Western Tuscany. Under a broader point of view, this trend can be framed up in the sphere of activities wanting to contribute to the rescue of architectural buildings and constructions forrning the exceptional cultural heritage. This heritage is characterising bath the Tuscanian territory and the landscape, seen as precious and wise Environmental Resources to be preserved tor future generations, as far as it is still possible.

With the development of road and railways transports in the Aquitaine region (France) and for a better efficiency, the SNCF, RFF (the french railway company) decided to build a new multimodal transport exchange platform. The kept hold site is situated in the vicinity ofthree highways (Paris, Spain and Méditerrannée) and of an existing marshalling yard.