共查询到20条相似文献,搜索用时 15 毫秒
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Geschäftsführender Gesellschafter Richard Stroetmann Dr.-Ing. Niederlassungsleiter Andrej Albert Prof. Dr.-Ing. 《Bautechnik》2005,82(6):339-354
Design and construction of the Al-Sadd Stadium in Doha, Qatar. The stadium of Al-Sadd Sports Club, which is the most famous soccer club of the state of Qatar, has recently been upgraded and in large parts been reconstructed from scratch within a period of 14 months. The paper describes some specific features of the design and the construction of this project. The issue of lateral torsional buckling of the curved roof structure and the respective calculations are addressed in detail. 相似文献
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Mathilde Koscielny 《Bulletin of Engineering Geology and the Environment》2008,67(4):585-595
This work focuses on the interaction between human activity in mountainous areas and slope movement hazards. The paper considers
the triggering factors and processes of instability in the urbanized area of Les Arcs, an area exploited for mass ski runs
and where many debris flows have occurred over the last 40 years. A progressive survey of the geological, geomorphological,
hydrological, hydrogeological and climatic contexts is necessary to tackle the complexity of the phenomena. The human impact
is considered as well. From the analysis, the geology associated with a specific climate was determined to be the main triggering
factor for debris flow hazards. The influence of the glacial and postglacial period on the geomorphological aspects (e.g.
steep slopes) and on the mechanical component of the superficial formations is the main factor. Furthermore, an analysis of
regional meteorological data over the last 5 decades has emphasized a significant evolution of the climate since the 1960s
which resulted in a general increase in temperature, rainfall (with seasonal variations) and the occurrence of extreme weather
events, with long term implications for erosion and on water balance. This seems to be exacerbated by recent human activities
which have significantly changed the natural environment: deforestation, changes in vegetation, the development of impervious
surfaces such as roofs, roads and car parks, the creation of ski runs and the intensive exploitation of the catchment, all
of which may have an influence on runoff and erosion affecting the natural surface structure. These changes and their effects
on such factors as runoff and erosion have been reviewed and analyzed. In particular, the effects on hydrology have been highlighted
by a hydrological modeling created using PCRaster Environmental Software. The hydrology of the Ravoire torrent before the
creation of the ski resort was compared with the present configuration of the catchment. The annual water balance model shows
that the ski resort generates a significant increase in the river flow compared to that before the change in land use. The
parametric analyses undertaken revealed that the deforestation, the development of ski slopes and impervious areas are responsible
for the reduction in infiltration inducing runoff. The maximum increase in water flow occurs during periods of natural high
water flow (during snow melt) when the risk of debris flows is naturally high. For the last 20 years, this phenomenon has
been amplified by the increasing production of artificial snow on the ski runs. Finally, a complementary model was created
to consider the effects over a short time scale. The results of this rain event model emphasize the change in the hydrological
response of the rivers after rainfall as a consequence of the change in land use. In particular this indicated a rise in the
peak flow towards the resort, which may activate erosive processes above the debris flow source areas.
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In the Black Forest, mineral waters from five wells in crystalline basement (granite and gneisses), their probable source rocks and the experimental leachates were evaluated for rare earth elements (REE), yttrium contents, and lead isotope ratios. The distribution of REE and Y, and the Pb-isotope ratios are powerful tools to identify the most likely type of rock that controls cation contents of the mineral water. Granites and gneisses lead to REE patterns with varying negative europium anomalies in waters; i. e., gneisses have a tendency for positive or only slightly negative europium anomalies in fluids, whereas granites exhibit negative anomalies. The comparison of REE and Y in the leachates and waters shows that these elements are characteristically redistributed during water-rock inter-action between rock-forming and accessory minerals, surface layers and adsorption films. REE and Y are leachable in the aquifer rocks, in which light REE are partially impoverished. REE and Y in samples from surface outcrops show enhanced leachable fractions. In alterated rocks, large fractions of 206 Pb are definitely leached from other solid phases than 207 Pb and 208 Pb. 相似文献
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Philippe Masure 《Bulletin of Engineering Geology and the Environment》1995,51(1):129-137
Instability of underground excavations and karsts generally leads to violent events that affect zones which are difficult to locate precisely. For this reason, monitoring and alarm systems are not very efficient and risk management must therefore be essentially focused on prevention. In France, the aim of such prevention is to find a balance. Although the French legal and regulatory framework is rational, it is deficient in certain respects, and particularly faces difficulties concerning implementation as revealed by the development of the Plans of Exposure to Risks (PER) having taken too long. The comments made during the symposium held at Nainville-les-Roches have lead to the proposal of a number of improvements for the present system: -promote a global approach which integrates risk management into land-use planning, ensuring coherence between national, regional, departmental and local plans, -develop an operational approach for each “basin” at risk, -speed up hazard mapping by its separation from regulatory procedures, -develop plans for crisis management at a municipal level; bring experts, technical services and emergency services closer together and involve populations at risk in the preparation process, -launch an operational information policy on the risks and develop a true culture of risk prevention, -set up a local public service responsible for risk management of underground excavations within areas of greatest risk. 相似文献
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Ralph Schöpke Roland Koch Indra Ouerfelli Angelika Striemann Volker Preuß Ralf Regel 《Grundwasser》2001,6(1):23-29
Acidic conditions of seepage and groundwater originating from open pit minings in Lusatia are described using the neutralization potential, which is based on the concept of acidity. Acid formation and buffer reactions can be reduced to three elemental reactions: oxidation of pyrit/reduction of sulfate, dissolution of carbonate and gypsum equilibrium. These reactions are combined in a genetic model in order to interpret the origin of mineral and acid contents of different groundwaters influenced by lignite mining. The statistical results of these calculations are summarised in order to calibrate parameters of a prognostic model. The method described here is used to prepare restoration measures. 相似文献
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Toulemont Marcel 《Bulletin of Engineering Geology and the Environment》1987,36(1):89-100
A sewage collector can be considered as a composite structure, comprising the collector itself and its geological envelope both sticking together. Its durability is directly linked with the geotechnical behaviour of the soil, as testified by the analysis of numerous pathological cases observed in structures which it is possible to inspect in the Paris urban area. The author proposes a methodology enabling these parameters of influence to be taken into account without recourses to costly procedures of investigation. Based on the principles of mapping risks of soil movements, the method involves two stages: -The geotechnical classification of soils in terms of their vulnerability to stresses to which they may be subjected. -The establishments of maps or profiles predictive of risks. in accordance with qualitative criteria derived from the interpretation of existing geological information. Tested and applied to the inspectable sewage system of the Val-de-Marne and Seine-Saint-Denis Departments, this procedure can be extended to urban systems where sufficient geotechnical documentation is available to obviate the need for any in situ investigation. 相似文献
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Kfz-Stellpl?tze in einer Entfernung von 940 m liegen nicht mehr im "Umkreis von zirka 500 m". Auf Besonderheiten eines Bezirkes
oder Bezirksteiles (hier: der Wiener Innenstadt) kann in diesem Zusammenhang nicht Bedacht genommen werden. 相似文献
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This study was initiated in order to investigate relationships between the arsenic species distribution, the geochemical conditions and the input source of As in groundwater. Water samples characterized in the study originated from four locations representing five different input sources. The redox conditions varied vrom oxid to sulfidic. Measurements indicate – as expected – that the As(III)/As(V)-species distribution is closely related to the redox environment. Nevertheless it cannot be predicted using the redox potenzial and the Nernst equation. Results clearly reveal a dependence of the species distribution on the As input species. Related to the redox conditions, an oxidation path of As(III) can be distinguished from a reductuion path of As(V). The kinetics of the redox reactions depend on the availability of reaction partners. 相似文献
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The object of this laboratory study was to determine any relationship between the soil volumetric water content θ, the dielectric constant (permissivity –ε), and the impedance of the same soil (R1). Time domain reflectometry (TDR) allows the measurement of material dielectric constant and impedance by determining electromagnetic pulse transit time and pulse attenuation. Using the established relations of the TDR method, it is possible to trace the volumetric water content and electric conductivity (or the impedance) of the soil simultaneously in a continuous manner. It was hoped that, thereafter, it may be possible to calculate the soil suction using soil permissivity and impedance. TDR measurements were carried out for different leachates and soils. Relationships found in previous work by the authors were used to compare water contents given by the TDR method with water contents obtained by drying the soil samples. The test results showed a relationship between water content and soil type and the electrical conductivity of the liquid when the TDR parameter was soil impedance. It was concluded that permissivity could be used to characterise the soil's water content. This relationship is used to study the changes in bentonite water content during air drying. Volumetric water content and impedance vs time curves allows the determination of shrinkage limit. 相似文献
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Réda Kechairi Benamar Benmahioul 《The International journal of environmental studies》2013,70(5):800-814
Cette étude avait pour but d’évaluer le comportement de l’Arganier en plantation sur site in situ dans son aire de répartition naturelle et aux endroits ex situ, dans la région sud-ouest Algérienne. Les résultats obtenus ont montré que les meilleurs taux de reprise ont été enregistrés à Adrar et Timimoun avec respectivement 85 et 80%. En ce qui concerne la croissance, les plants poussant dans la pépinière d’Adrar ont donné la longueur moyenne des tiges la plus élevée (51,3 ± 4,1 cm). Après 16 ans de transplantation, nous signalons le bon comportement de l’Arganier dans les différents sites ex situ. Les mesures dendrométriques des sujets ont donné un accroissement moyen annuel en diamètre de 0,55 centimètre pour une hauteur de 0,23 mètre. 相似文献
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A natural gradient multitracer-experiment (fluorescein, eosin, naphthionate, bromide) was performed at an experimental site with contaminated groundwater. The break-through curves were evaluated by fitting an analytical solution of the transport equation to the breakthrough curves, different calculation methods based on the tracer arrival times, and with numerical transport simulations. The observed transport direction differed markedly from the expected direction based on equipotential lines. The method of temporal moments proved to be best suited to describe the transport velocity. Transverse dispersivites could not be evaluated satisfactorily, even though numerous observation wells existed. The interactions of the tracers and nonaqueous phase liquids (octanol, tar oil, lubrication oil) were investigated with laboratory experiments. None of the tracers was affected. Fluorescein and eosin could be applied successfully even when nonaqueous phase liquids were present, but the application of naphthionate suffered from high background fluorescence. 相似文献
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Philipp Magiera 《Grundwasser》2000,5(3):103-114
The increasing threat of groundwater contamination by pollutants has led to the development of methods to assess groundwater vulnerability on a regional scale. An assessment of groundwater vulnerability will also be required by the coming EU framework directive on water. The concept of groundwater vulnerability is discussed and available methods are presented. These include hydrogeological complex and setting methods, analogue relations and index methods, point rating and matrix systems, mathematical models and statistical approaches. The methods and their principal characteristics are explained and summarised with emphasis on their regional usability. 相似文献
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Die Einwendung des anrainenden Betriebsinhabers, dass er "ein rechtliches Interesse daran (hat), dass durch faktisches Heranrücken
von als Wohnungen genützten Objekten an seine Betriebsanlage seine gewerberechtlichen Befugnisse nicht (zus?tzlich) beeintr?chtigt
werden", stellt keine Einwendung im Rechtssinne dar, weil daraus nicht zu erkennen ist, in welchem geschützten subjektiv-?ffentlichen
Recht sich der Nachbar durch die beabsichtigte Bauführung für verletzt erachtet. 相似文献
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Detlef Hebert 《Grundwasser》1999,4(4):155-164
The complex application of isotope physical measuring methods together with model calculations for groundwater flow and hydrochemistry is helpful to estimate groundwater vulnerability. Thereby Tritium is used as a natural tracer of local groundwater input indicating a possible groundwater vulnerability, and the far-reaching, long-term groundwater migration is derived from Carbon-14 ages of dissolved inorganic carbon. For the case “double-porosity aquifer (Finne Bunter Sandstone, Saxonia-Anhalt)” the derivation of hydrogeological parameters as groundwater recharge, groundwater flow and the water exchange rate of an aquifer is demonstrated. Especially information on the groundwater vulnerability can be obtained without any real groundwater contamination. 相似文献
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Die Herkunft der Salinit?t in Grundgebirgsw?ssern wird in der internationalen Literatur heftig diskutiert. Für eine Anreicherung
von Chlorid gibt es mehrere M?glichkeiten: Herkunft aus dem Gestein (Mineralgitter, Fluideinschlüsse, Korngrenzen) aus benachbarten
salinaren Ablagerungen, aus einer Intrusion von Meerwasser. Anhand der Cl/Br-Systematik wird gezeigt, dass die hohe Salinit?t
der Thermalw?sser des Schwarzwaldkristallins im Gegensatz zu anderen Kristallinw?ssern genetisch haupts?chlich auf einer Intrusion
von Meerwasser beruht. Ein Eintrag aus salinaren Ablagerungen des Terti?r im Oberrheingraben oder aus dem Muschelkalk kann
ausgeschlossen werden. Die marine Herkunft belegen auch die molaren Verh?ltnisse von Na und Cl, die Beziehung zwischen Na
bzw. Cl und TDS im Vergleich zur Meerwasserverdünnungslinie. Einen entscheidenden Beitrag zur Wasserchemie aller Grundgebirgsw?sser
liefert die Verwitterung von Plagioklas, insbesondere seiner vergleichsweise gut l?slichen Anorthitkomponenten. Zum Chemismus
der Grundgebirgsw?sser tragen weiterhin die Verwitterung von Biotit mit Freisetzung von Li, F und K sowie die Wechselwirkung
des Wassers mit K-Feldspat bei. 相似文献