Zur Gleichsetzung der Technikklauseln mit ÖNORMEN

Obwohl der Gesetzgeber in den Kernbereichen des Privatrechts nicht ausdrücklich auf den Stand der Technik oder auf vergleichbare andere Technikklauseln abstellt, werden doch die einzelnen zivilrechtlichen Generalklauseln durch den OGH gerade in den für das Baugewerbe besonders bedeutsamen Bereichen des Werkvertrags- sowie des Schadenersatzrechts unter Heranziehung von Technikklauseln ausgelegt. Dabei bestimmt der OGH in stRsp den Inhalt der verschiedenen Technikklauseln in nicht wenigen F?llen durch einen grunds?tzlich undifferenzierten und nicht n?her begründeten Rückgriff auf die unterschiedlichen technischen Regelwerke im Allgemeinen und auf die ?NORMEN im Besonderen. Aus Anlass einer aktuellen, den hier interessierenden Problemkreis berührenden Entscheidung des OGH sowie einer jüngeren, sich mit den allgemein anerkannten Regeln der Technik auseinandersetzenden und diese Frage ebenfalls aufgreifenden Arbeit soll im vorliegenden Beitrag den Ursachen für diese Gleichsetzung von Technikklauseln und ?NORMEN durch das H?chstgericht nachgegangen und die dogmatische Unhaltbarkeit des vom OGH vertretenen Ansatzes nachgewiesen werden.     

Grundwasserfließgeschehen Mecklenburg-Vorpommerns – Geohydraulische Modellierung mit Detrended Kriging

Groundwater heads were mapped for the entire State of Mecklenburg-Western Pomerania by applying a Detrended Kriging method based on a numerical geohydraulic model. The general groundwater flow system (trend surface) was represented by a two-dimensional horizontal flow model. Thus deviations of observed groundwater heads from simulated groundwater heads are no longer subject to a regional trend and can be interpolated by means of Ordinary Kriging. Subsequently, the groundwater heads were obtained from the sum of the simulated trend surface and interpolated residuals. Furthermore, the described procedure allowed a plausibility check of observed groundwater heads by comparing them to results of the hydraulic model. If significant deviations were seen, the observation wells could be allocated to different aquifers. The final results are two hydraulically established groundwater head distributions – one for the regional main aquifer and one for the upper aquifer which may differ locally from the main aquifer.     

Bauplatzbewilligung; Grundstück mit verschiedenen Flächenwidmungen

Auf einem Grundstück dürfen grunds?tzlich nicht mehrere Baupl?tze bewilligt werden. Ist ein Grundstück zum einen Teil als Bauland zum anderen Teil als Grünland gewidmet, ist die Erteilung einer Bauplatzbewilligung nur für den als "Bauland-Wohngebiet" gewidmeten Teil des Grundstückes aber durchaus zul?ssig.     

Grundwassergleichenplan für Brandenburg – Interpolation mittels Kriging mit externer Drift

In Brandenburg, Germany, state-wide water table contours that are based on data at a common reference date were created for the first time. These contour maps are needed as a basis for hydrological and hydrogeological analyses. All hydraulic heads were measured in 2011 using data from the regional authority and from about 100 other official institutions. Regionalisation was achieved with geostatistical interpolation using “kriging with external drift”. Additional information exists in terms of a conceptual model, which characterises water table contours and was used as a secondary variable in the kriging process. This method provides a significantly better approximation of the groundwater system in comparison to ordinary kriging while decreasing the number of required supporting points and improving reproducibility. The water table contours of 2011 can be used as a basis for external drift in future mapping campaigns, which will help to reduce the need for field measurements and mapping.     

Entwurfsparameter für fugenlose Betonbrücken mit gekrümmtem Grundriß

Parameters for designing jointless concrete bridges with curved geometry in plan The curved geometry in plan shall be advantageously combined with the jointless construction method. Constraints due to temperature and shrinkage can be considerably reduced by horizontal “relaxation” (movement) of the superstructure. In this way complicated concrete technology and constructive measures on site can be avoided to decrease cracking and reduce costs. Additionally it offers an improved aesthetic. The following contribution shows, that few parameters are sufficient for designing curved concrete bridges without bearings and joints.     

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.     

St.-Lorenz-Brücke in Lübeck – Flacher Bogen mit besonderem Montageablauf

In Verbindung mit der Elektrifizierung und dem zweigleisigen Ausbau der Bahnstrecke Hamburg–Lübeck-Travemünde wurde die St.-Lorenz-Brücke in Lübeck durch einen neuen Brückenzug ersetzt. Wesentlicher Bestandteil ist eine sehr flach entworfene Stabbogenbrücke, die das Gleisbett in unmittelbarer Nähe zum Lübecker Hauptbahnhof überspannt. Im folgenden Beitrag wird die Planung und Ausführung des Brückenzuges beschrieben und auf Besonderheiten der Tragwerksplanung und Montage der Stabbogenbrücke eingegangen (vgl. [1]). St.-Lorenz-bridge in Lübeck, Germany – Low arch with a special erection process. Due to the electrification and the two-track extension of the railway line Hamburg – Lübeck-Travemünde the St.-Lorenz-bridge was replaced by a new multi-span-bridge. Significant component is a very low bowstring bridge, which spans over the railway line near main station Lübeck. In the following article design and execution of the bridge structures are described as well as special features of structural design and erection of the bowstring bridge (comp. [1]).     

Vorschlag für die Bemessung der Deckenknoten mit Stützen aus hochfestem Beton

Design Approach for effective Strength of Column-Slab Joints between Columns of High-Strength Concrete At present the German concrete construction standard contains no approach for the prediction of the load transfer mechanism from columns of high strength concrete (HPC) through floor slabs of normal strength concrete (NSC). In this paper a design approach due to test results with high slab loads is presented. Because of the small amount of the conducted tests in this and in other published programs, the proposed equation appears to be on the safe side, compared with the design approach in the ACI code, that is based on experiments with unloaded slabs.     

Messung der Infiltrationsgeschwindigkeit von Oberflächenwasser mit Hilfe des natürlichen Isotops Radon-222

Owing to its different concentrations in groundwater and river water, the naturally occuring isotope radon-222 can be used as a natural tacer to determine the residence time of freshly infiltrated water and the infiltration velocity. In the study area, predominant correlation was found between the radon activity concentration of groundwater and the lithologic structure of the aquifer. Misinterpretation of low radon activity concentration measured near surface waters due to geological inhomogeneities can result in false assumptions about groundwater flow paths. The infiltration of river water into the adjacent aquifer during a flood wave was also ascertained by measuring radon activity concentration. Further the residence time of infiltrated water was determined at a sampling point installed beneath the river Elbe and infiltration velocity was calculated.