The current floating bridge concepts of Norwegian Public Roads Administration (Statens vegvesen, NPRA) use a flange shape part at the bottom part of the pontoons. The flange is in principle similar to the damping plates used in the offshore industry for SPAR type of structures. The project group initiated the flange part based on the requirement of extra added mass for tuning the bridge system Eigen-modes. Thus, the important modes can be shifted out of the main wave energy zone. The current study will focus on the damping effects of such structure. The damping effects on weak axis bending moment prediction is studied. The modelling of such damping is first proposed according to relevant literature based on both numerical and experimental studies. Since the reference studies were mainly focused on cylindrical structures, it is difficult to obtain an accurate estimation of the damping coefficient for the current bridge pontoon design, which contains a rectangular part between two half-cylindrical parts. In addition, the estimation of pontoon motions needs the input of damping coefficient, which means that the evaluation of damping coefficient is an iteration process. In order to include the uncertainties, a conservative value was adopted to represent the damping effect. The comparison of accounting for the damping effects or not has been given for all the bridge pontoons. The results show that the damping effects are important at the peaks of the responses; in addition, the reduction of the predicted maximum bending moments can be expected around 10–15 percent along different positions of the bridge. However, a further investigation also shows that viscous excitation would increase the bending moments slightly. The comparison also indicates the value of further investigating the effects by CFD or model test methods.
Danish university students are often criticised for a general lack of proficiency in orthography, punctuation and grammar in the academic register. However, there has been limited empirical substantiation to support the claim. In this paper, we present the results of a study of linguistic deviations in university assignments written by first-year Journalism and Danish students at the University of Southern Denmark (N = 100 students). The results show that the majority of both groups struggles with Danish orthography and punctuation when writing academically, which seems to confirm some of the assertions made by the critics. However, it is argued that the inherent conflict of orthographic and punctuation principles in Danish as well as the specific characteristics and challenges of academic writing are more probable causes than the claimed general decline in the writing proficiency of students.
Concrete offshore platforms have been used successfully in the North Sea s~nce 1973. Considerable effort has been made in various fields to improve and optimize the design of these platforms. The paper concentrates on the development of high-strength concrete and its consequences for design. This development has focused on producing concrete of higher quality and on obtaining knowledge of the major properties of the concrete in the existing platforms. The data basis for such knowledge is extensive. Nearly 2 million m 3 of concrete have been produced for the North Sea platforms, and the quality and performance extensively monitored through rigorous quality assurance systems and in-situ tests. The data indicate that the obtained quality in the platforms is high, uniform and predictable and that it exceeds the requirements of the design specifications with ample margins.The data and experience obtained suggest higher util ization of high-strength concrete than allowed in most design codes. This may result in significant material saving and more cost-effective structures, particularly for deepwater platforms.References and illustrations at end of paper.
<p>The COWI Team prepared in 2007 Basic Design and construction cost estimates for Hålogaland Bridge. The bridge is arranged as a single span suspension bridge with A-shaped concrete pylons, inclined cable planes and a closed steel box girder as bridge deck. The combination of a slender bridge and 2.2m high safety railings to prevent would-be-suicides jumping on impulse from the bridge poses a severe design challenge to fulfil the aerodynamic stability requirement of 56m/s at bridge deck level. The issue of vortex induced vibrations for closed steel box bridge decks poses another design challenge. The box section is arranged in such a way that the slope of the lower inclined side plates is at 15.8 degrees in relation to the horizontal bottom plate. Wind tunnel tests carried out in smooth flow have proved that vortex induced vibrations will not occur, thus saving the costs of installation and maintenance of mitigation measures.</p>
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