Ground zoning against seismic hazard in Athens, Greece

The 1999, Ms=5.9, Athens earthquake caused serious structural damage to buildings in the western part of Athens, Greece. This paper presents the ground zoning against seismic hazard proposed shortly after the earthquake in order to aid reconstruction of the area. Existing engineering geological and geotechnical data were combined with local observations to provide a unified set of classification criteria, consistent with provisions of the Greek Seismic Code EAK. The accuracy and the possible limitations of this zoning procedure are addressed through comparison with observed damage distribution as well as results from seismic ground response analyses performed at sites with well established soil profiles. There is clear evidence that the proposed zones correspond to geological formations exhibiting grossly different seismic response with regard to the design of common engineering structures. However, the mostly qualitative nature of the guidelines for ground categorisation provided by EAK and the general lack of systematic, site-specific geotechnical data for the whole area induce uncertainties in the definition of the seismic design actions for the different zones. These objective uncertainties certainly demand increased conservatism but do not limit application of the proposed methodology for first aid, preliminary planning in the event of destructive earthquakes.     

Brittle-Ductile Transition and Hoek–Brown mi Constant of Low-Porosity Carbonate Rocks

Geotechnical and Geological Engineering - The mechanical behavior of low porosity carbonate rocks is investigated by a series of conventional triaxial compression tests performed at room...     

Effects of smoking on the levels of urinary biomarkers of aromatic hydrocarbons in oil refinery workers

Occupational exposures to aromatic hydrocarbons may be overwhelmed by mainstream and secondary smoking exposures. The objective of this study was to evaluate the influence of occupational exposures and smoking on benzene and toluene urinary metabolites. The metabolites were measured in pre and post-work shift urine specimens in oil refinery workers by gas chromatography/mass spectrometry techniques. Post-shift concentration differences between non-smokers and smokers were statistically significant (at p-value?<?0.05). Pre- and post-shift concentrations of urinary phenol (benzene biomarker) did not vary significantly for both non-smokers and smokers. Occupational exposures to toluene triggered an increase of post-shift levels (compared to pre-shift levels) of urinary cresol for non-smokers and workers who had less than 10 cigarettes during the work shift. For these groups, non-occupational exposures before and during the work shift did not vary. For smokers who did not smoke during the work shift and for those who had more than ten cigarettes during the shift, the post-shift levels of both cresol and hippuric acid were reduced approximately 30% lower than pre-shift levels. This is due to increased exposures to tobacco smoke before the work shift. The relationships between phenol and (cresol?+?hippuric acid) levels for non-smokers and smokers indicated that elevated co-exposures due to smoking result in the reduction of all metabolites levels in urine. These findings demonstrated that exposures to tobacco smoke may stochastically interfere with occupational exposures when biological monitoring is used to assess occupational health risks. Factors influencing the magnitude of the interference were specimen collection time (in relation to the timing of occupational exposures and excretion rates of biomarkers), smoking intensity and timing before and during the work shift.     

Ground fissures in the area of Mavropigi Village (N. Greece): Seismotectonics or mining activity?

In the beginning of July 2010, a ground fissure was observed in the field near the village of Mavropigi (Northern Greece) and specifically in its NW side. Later on (early September), a second ground fissure was perceived, close and almost parallel to the first one and very close to the limits of the lignite exploitation mine (by the Public Power Corporation, PPC). It was observed that the village of Mavropigi slides away slowly towards the PPC lignite mine. Geological, seismological, as well as geotechnical survey in the field indicated that the phenomenon is related to the coal mining exploitation in the near vicinity of the village rather than to any seismotectonic activity in the surrounding area.     

Building stones and geological environment in three ancient cities of Aegean Thrace,Greece

The type, use, and size of the structural stones employed in three ancient cities of the Aegean Thrace are considered Abdera, Maroneia, and Mesimbria. The impact of the geological environment on the choice of these materials also is examined. From the results obtained it is implied that despite the great variety of rocks exposed in the area, the rocks used in construction in these cities are mostly types of sandstone and limestone, rocks with moderate technical properties and easily obtained from the area. The quarries were within a radius of less than 10 km and the size distribution of the building stones in all towns is discussed.