Zerstörende Belastungsversuche an einer vorgespannten Segmentbrücke

Ultimate Load Tests on a Post-Tensioned Segmental Bridge In 1975, the construction company A. PORR A.G. was commissioned by the Austrian Ministry for Construction and Technology with a research project involving the erection of a segmental bridge structure with cemented and pre-stressed joints across the Süd-Ost-Tangente motorway section in Vienna. The single-span box girder bridge with a span of 44 m was composed of 18 prefabricated segments. The bridge structure was subjected to bending by applying a single load, which was gradually increased to a maximum of 2.000 kN, in the middle of the span. The load was applied on a steel girder placed across the carriageway with jacks at both ends. Cables that were bolted to the middle wall of Absberg tunnel and to the jacks permitted controlled loading of the structure. Overall, a total of ten load tests were completed. Between the individual loading phases the tensioning cables were cut at various points to simulate the impact of damaged cables on the load-bearing capacity and the deformation of the structure. The opening widths of the joints between the segments, deformation on the top and the bottom of the structure, the elongation of the reinforcements and the deflection were measured, evaluated and analysed in a continuous process.     

Abwasserbeseitigung; Güllegrube; subjektiv-öffentliche Nachbarrechte

Die Gesamtkosten der Errichtung des Anschlusses an den Regenwasserkanal in der H?he von EUR 3.561,– stehen mit rund 11% in keinem Missverh?ltnis zum Verkehrswert des anzuschlie?enden Geb?udes. Die Verrieselung bzw das Versickern von Niederschlagsw?ssern stellt keine "Kanalisationsanlage" dar, die die ?rtlichen und regionalen Gew?sserschutzziele zumindest im gleichen Ausma? wie die ?ffentliche Kanalisationsanlage erfüllt.     

Bohrlochgeophysikalische Messung der Grundwasserbewegung bei minimaler Störung des natürlichen Strömungsfeldes

The quantification of groundwater flow behaviour is an important issue in the fields of groundwater and environmental protection as well as in the field of construction engineering. In this context, knowledge of the parameters of the groundwater flow field is critical for the evaluation of flow patterns, for the definition of water protection areas and drainage activities, and for the assessment of risk potential. It is also fundamental for modelling and monitoring purposes. This paper presents a new single-well borehole measurement system for the investigation of groundwater flow directions and velocity. It can be used to measure velocities greater than 0.5 m/d. The measuring principle is based on the creation of a defined tracer signal within the well screen of a monitoring well and observation of the time-dependent change of the tracer-induced conductivity and temperature anomalies in the near and far field. To measure these two parameters, geoelectrical arrays and temperature sensors are used. A new technique was developed that creates a homogeneous tracer distribution in the annulus between the probe and casing, with only minimal disturbance of the natural flow field. The tracer density is adapted to the groundwater and thus avoids density driven convective processes.     

Grundwasserströmungsmodell für den Großraum Rhein-Neckar

MVV Energie AG had to reapply for the rights of groundwater withdrawals in the areas of the waterworks Mannheim Rheinau and Mannheim Käfertal. A numerical steady-state flow model was set up to support the request for new water rights. The simulation model was used to evaluate the planned withdrawal and its effects on groundwater flow. It was adjusted to average and low groundwater level. The calibration was performed by long-term comparing simulated to observed data. The calibrated model was used to predict the effects of different withdrawal scenarios. The paper exemplifies effects of an enhanced withdrawal for the wells of the waterwork at Rheinau. The simulation model assisted in delineating the area for the environmental impact assessment process. Furthermore the delineation of the catchment zones shows that the existing protection zone III is too small. Currently the extension of the legal protection zones is proposed to the authorities. The new eastern boundary will be the mountains of Odenwald, while the protection zone will be reduced in the northern area.     

Die Entwicklung der körperschall- und erschütterungsdämmenden Oberbaukonstruktionen beim Münchner U-Bahn-Bau

Development of structure-born noise and shock insulating superstructures at the Munich subway construction. Since the start of the subway construction in Munich in 1965, the structure-born noise and shock insulating superstructures reached a continually evolving standard until today. About the close cooperation between the client and science and the experiences of more than 40 years subway construction in Munich are reported.     

Radon im Grundwasser des Mühlviertels (Oberösterreich)

In the occurrence areas of selected crystalline rocks—mainly granites—the Radon-222 content of groundwater has been investigated. The results show a significant correlation with the Uranium concentrations in the rocks. The Uranium concentrations were between 1 and 15 ppm, while the Radon-222 concentrations were between 0.2 and 719.5 Bq/l. To identify Radon-decreasing effects like degasification and admixture of surface water, CO₂ partial pressures and Oxygen-18 in water samples were determined and the local hydrological situation has been taken under consideration. Samples which showed clear evidence of Radon-decreasing effects were excluded from further evaluation because they would not represent the full empiric potential of Radon emanation in the aquifer. In combination with geological maps, petrologic information and airborne radiometry, Radon-222 analyses in groundwater can provide important data for Radon potential mapping. The significance of the groundwater Radon analyses can be improved by supplementary hydrochemical and hydrological isotope investigations.     

Referenzprojekte; Ausführung durch Dritte; Ermittlungspflichten der Vergabekontrollbehörde

§32 Abs 1 Z 1 GewO erlaubt allen Gewerbetreibenden und damit auch dem Baumeister, Leistungen anderer Gewerbe, die die eigene Leistung wirtschaftlich sinnvoll erg?nzen, "in geringem Umfang" zu erbringen.     

Isotopenanalytische Charakterisierung tiefliegender Grundwässer im Raum der Fürstenwalde-Gubener-Störungszone

Isotope variations were studied especially in deep situated groundwater wihtin the hydrogeological complicate fault zone of Fürstenwalde-Guben. ¹⁴ C, tritium and δD values were compared with hydrochemical data. A good correlation was found regarding depth profiles as well as between the related mean values classifying all samples by their chemical composition in five groups. The lowered mean deuterium contents of the samples of one group show an influence of water, formed in cooler climatic periods. On the other hand deuterium is frequently enriched in the most mineralized waters. The effect of coal degradation processes by aerated waters on the radiocarbon content is demonstrated regarding a case study in a small coal basin near Leipzig with former underground mining.     

Folgen des Globalen Wandels für das Grundwasser in Süddeutschland – Teil 2: Sozioökonomische Aspekte

In order to account for complex interactions between humans climate and the water cycle, the research consortium GLOWA-Danube (www.glowa-danube.de) has developed the simulation system DANUBIA which consists of 17 coupled models. DANUBIA was applied to investigate various impacts of global-change between 2011 and 2060 in the Upper Danube Catchment. This article describes part 2 of an article series with investigations of socio-economic aspects, while part 1 (Barthel et al. in Grundwasser 16(4), doi:10.1007/s007-011-01794, 2011) deals with natural-spatial aspects. The principles of socio-economic actor-modeling and interactions between socio-economic and natural science model components are described here. We present selected simulations that show impacts on groundwater from changes in agriculture, tourism, economy, domestic water users and water supply. Despite decreases in water consumption, the scenario simulations show significant decreases in groundwater quantity. On the other hand, groundwater quality will likely be influenced more severely by land use changes compared to direct climatic causes. However, overall changes will not be dramatic.     

Erkundung der regionalen Grundwasserströmung im Muschelkalk Mittelwürttembergs mit stabilen Umweltisotopen

In the city of Stuttgart, several artesian springs discharge carbonic acid enriched mineral water of variable total mineralization at a rate of about 500 l/s. The springs are part of the regional aquifer system in the karstified Upper Muschelkalk. To clarify their genesis and origin, measurements of the stable isotopes δ ¹⁸ O and δ ² H were used. They allow conclusions on the regional groundwater flow system and on the geochemical evolution of the mineral water. Mainly responsible for contrasts in isotope measurements of the 4500 km ² area is the altitude effect. It was determined for δ ¹⁸ O with a depletion of about ?0.4‰ per 100 m increasing altitude. Similar isotope values in western parts of the Fildergraben (recharge area) and in Stuttgart are explained with a low mineralized groundwater flow. The higher mineralized water which is strongly depleted in δ ¹⁸ O is a result of a mixing process with other aquifers in the discharge area.     

Zerstörungsfreie Prüfung im Bauwesen: Automatisierte Messungen mit Radar,Ultraschallecho und Impact-Echo an der Fuldatalbrücke

Non-Destructive Testing in Civil Engineering: Automated Testing with Radar, Impact-Echo and Ultrasonic Echo at a PT-Bridge across the river Fulda Stability and durability of post-tensioned concrete bridges are mainly determined by the state of the reinforcement and the tendons. Detailed information about the kind and the extension of damages or about suspected non-visible damages have to be gained through additional analyses on object level. The number of the destructive tests can be significantly reduced by application of efficient non-destructive test methods. The efficiency of automated non-destructive test methods radar, impact-echo and ultrasonic echo has been demonstrated by measurements on the bridge “Fuldatalbrücke” near Eichenzell. The methods were applied to detect the reinforcement, internal tendons and to locate possible voids in the tendon ducts. The results of the investigations are presented in a number of images.     

Stochastic seismic analysis of Kömürhan Highway Bridge with varying material properties

Stochastic seismic finite element analyses of the Kömürhan Bridge, the material properties of which are described by random fields, are presented in this paper. The stochastic perturbation technique and Monte Carlo simulation (MCS) method are used in the analyses. A summary of MCS and perturbation-based stochastic finite element dynamic analysis formulation of the structural system is given. The Kömürhan Bridge, located on the 51st km of Elaz??-Malatya highway in the east of Turkey, was chosen as a numerical example. The Erzincan earthquake in 1992 was considered a ground motion, since it took place in the vicinity of the bridge. The material properties were considered to be random variables. During the stochastic analysis, displacements and internal forces of the bridge under consideration were obtained using the perturbation-based stochastic finite element method (SFEM), as well as the MCS method. The selected random variables were elastic modulus and mass density. The efficiency and accuracy of the proposed SFEM algorithm were validated through comparison with results of the MCS method.     

Modeling groundwater flow in the agricultural area of Gümüşhacıköy (Amasya, Turkey)

The Gümü?hac?köy Plain is the most productive agricultural area in the central/northern part of Turkey. Although the Quaternary/Pliocene granular deposits beneath the Plain have formed an important aquifer/water resource, excessive pumping in the last two decades, mainly for irrigation, has resulted in a significant depletion of the reservoir with some 30% of the total resource being lost in the last 40 years. The paper reports a groundwater flow model developed to allow the sustainability of the groundwater resource to be monitored such that appropriate measures can be undertaken.