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News Article | January 12, 2016
Site: phys.org

The Norwegian Public Roads Administration has been toying with this idea for some time: if noise barriers are mounted directly on roadside guardrails, they can use existing foundations and posts, thus eliminating the cost of installing such elements all over again. Several types of guardrail are used on Norway's highway network. Railings on road bridges, for example, are designed to keep cars actually on the road, so these are not subject to the same requirements regarding yielding to the force of a crash as other types of guardrail. Many "stiff" guardrails already incorporate noise barriers, but the Public Roads Administration is now looking for a combined solution for yielding guardrails, which are the most common type of guardrail in use in Norway. Yielding guardrails absorb forces from collisions in order to reduce injuries. How can noise barriers be integrated into guardrails, and what materials should be used in them? The Public Roads Administration asked SINTEF, the largest independent research organisation in Scandinavia, to look into these questions, with the aim of ensuring that the design of these rails will satisfy guardrail requirements. SINTEF has now presented its analysis of one chosen solution concept, where aluminium panels are incorporated in the rails to act as noise barriers. "Aluminium is corrosion-resistant, the material is widely used in energy-absorbing systems in many applications and it can easily be worked and recycled. It has a good ability to reflect sound, and transporting it is also energy efficient because it is light in weight," says SINTEF scientist Dirk Nolte. In the hunt for good designs, Nolte's colleague Nguyen Hieu Hoang used a computer model to simulate what happens when vehicles collide with a yielding guardrail with a built-in noise barrier. "The combi-rail needs to have sufficient stiffness and at the same time sufficient ability to absorb energy that it satisfies current requirements for the protection of drivers and passengers in the event of a collision. Thanks to our tests on models, we can be sure that our proposals lie within these limits," says Hoang. The results of the analysis employ panels that match the height of the guardrail, which means that the barriers are no more than around 75 cm high. Responding to those who do believe that this solution will not provide adequate noise control, Magnhild Finnanger, a senior engineer with the Norwegian Public Roads Administration, Eastern Region, offers the following explanation: "Yielding guardrails are often sited where the terrain falls away from the road. On such stretches of road, many houses therefore lie below the level of the source of noise. Such houses can obtain effective noise protection even from low noise barriers that are located at road level. Guardrails can also provide a certain amount of noise reduction to house that lie just slightly below the road, and in such cases, they can act as one of several noise reduction measures." SINTEF Building Research scientist Nathalie Labonnote, a participant in this project, says that the nearer to the source of noise a barrier is located, the lower it can be. She emphasises that the combined solution will not be suitable for all stretches of road with guardrails, and that detailed noise estimates will have to be produced in order to predict the efficacy of the solution. Yielding guardrails are made of steel profiles. In addition to their impact-reduction abilities they are also intended to prevent vehicles hitting obstacles, rolling down steep slopes or ending up in rivers. According to Nolte, if noise barriers are installed, they can also improve road safety for two-wheeled drivers. "We have placed the noise barriers in such a way that they are mounted behind the guardrail post for the sake of simplicity. As well as reducing noise, this configuration can prevent cyclists who fall on the cycle path behind the rail from hitting posts. However, we also envisage a solution in which barriers are installed on the front of the posts, that is, on the side facing the road. Such a design would prevent overturned motorcyclists from colliding with pillars,which may result in a lethal type of impact." According to senior engineer Finnanger, the Public Roads Administration intends to start with testing designs that have been validated through virtual testing by SINTEF's computer model; that is, with noise barriers mounted on the rear of the guardrail posts. "How long will it be before we see the first combined guardrails and noise barriers on Norwegian roads?" "SINTEF is currently trying to bring in a Norwegian company to produce noise barriers for trial installations on certain stretches of road. As the public authority concerned, we want to see that all the technical specifications laid down by the report are open, as this will make them equally accessible to any company that wishes to produce such barriers," says Magnhild Finnanger.

Hoien A.H.,Norwegian Public Roads Administration | Nilsen B.,Norwegian University of Science and Technology
Rock Mechanics and Rock Engineering | Year: 2014

The Løren road tunnel is a part of a major project at Ring road 3 in Oslo, Norway. The rock part of the tunnel is 915 m long and has two tubes with three lanes and breakdown lanes. Strict water ingress restriction was specified and continuous rock mass grouting was, therefore, carried out for the entire tunnel, which was excavated in folded Cambro-Silurian shales intruded by numerous dykes. This paper describes the rock mass grouting that was carried out for the Løren tunnel. Particular emphasis is placed on discussing grout consumption and the challenges that were encountered when passing under a distinct rock depression. Measurement while drilling (MWD) technology was used for this project, and, in this paper, the relationships between the drill parameter interpretation (DPI) factors water and fracturing are examined in relation to grout volumes. A lowering of the groundwater table was experienced during excavation under the rock depression, but the groundwater was nearly re-established after completion of the main construction work. A planned 80-m watertight concrete lining was not required to be built due to the excellent results from grouting in the rock depression area. A relationship was found between leakages mapped in the tunnel and the DPI water factor, indicating that water is actually present where the DPI water factor shows water in the rock. It is concluded that, for the Løren tunnel, careful planning and high-quality execution of the rock mass grouting made the measured water ingress meet the restrictions. For future projects, the DPI water factor may be used to give a better understanding of the material in which the rock mass grouting is performed and may also be used to reduce the time spent and volumes used when grouting. © 2013 The Author(s).

Thakur V.,Norwegian Public Roads Administration | Degago S.A.,Norwegian Public Roads Administration
Geotechnical Engineering | Year: 2014

Sensitive clays are known to result in massive flow slides and thereby resulting in loss of human lives and damaging nearby transportation infrastructures. Flow behaviors of these clays are usually characterized by their undrained shear strength at their fully remolded state. Therefore, assessment of flow slides in sensitive clays is directly related to their remolded shear strength. In other words, the extent of flow slides is crucially influenced by the remolded shear strength of the sensitive clays. However, a seemingly small variation in remolded shear strength has significant alteration in the flow behavior of sensitive clays. This paper study this aspect using a novel and pragmatic test procedure referred to as the quickness tests. This test amplifies the smaller range of remolded shear strength in term of parameter called quickness. The test has an advantage of giving a better visualization about the behavior of sensitive clays. Based on relevant Norwegian landslides data, a quickness based criteria to asses the potential for occurrence of flow slides is proposed. Copyright © 2014 Southeast Asian Geotechnical Society (SEAGS). All Rights Reserved.

Ostlid H.,Norwegian Public Roads Administration
Procedia Engineering | Year: 2010

When is a Submerged Floating Tunnel competitive?The various elements in transport systems are most often selected on the basis of the lowest price for the alternatives being viaducts, bridges or tunnels or some combinations of these. The submerged floating tunnel will therefore have to compete with well known structures and therefore have a disadvantage since no submerged floating tunnel has yet to be built. A future owner is then faced with a risk not easily estimated on one hand, on the other hand this new alternative may have certain attractive features especially when environmental considerations become important. This paper presents these various advantages and also points out some obvious disadvantages with this new and challenging structure. A great step forward would be if a submerged floating tunnel were built somewhere. The proposed structure here in China would certainly generate a lot of interest and I suggest the involved parties should prepare for a large number of visitors. © 2010 Published by Elsevier Ltd.

Skorpa L.,Norwegian Public Roads Administration
Procedia Engineering | Year: 2010

The Norwegian coastline is rugged with long fjords, and exposed to wind and waves from the North Sea. The fjords represent barriers to crossing traffic, and thus also to industrial growth in the coastal regions. Because of the many ferry connections in coastal regions, the Norwegian Public Roads Administration has always been searching for new ways to cross the fjords by fixed connections. During the last years limits have been stretched with regard to the use of slender suspension bridges as well as long and deep sub sea rock tunnels. However, there are still many ferry connections left. These are the most extreme fjord crossings, where existing bridge building technology has to be developed further, and in addition, new knowledge and experience from offshore technology turns out to be of great importance. To develop new alternative fjord crossing methods, the Norwegian Public Roads Administration, Western Region, has organized a conceptual feasibility study of how to cross the wide and extremely deep Sognefjord. The experience from this study will be of great value to other fjord crossing projects as well. In addition, the study may be of interest to projects in scenic inland lake areas and urban waterfront areas. The feasibility study focuses on crossing alternatives based on the use of water as a bearing element of the bridge structures. It includes different crossing methods such as suspension bridges, floating bridges, submerged floating tunnels (SFT), and combinations of these. The results from these studies, with focus on the use of submerged floating tunnels, as seen from the owners point of view are discussed in the paper. The use of new technology raises questions with regard to safety of the structures as well as to the traffic. The study also gives important knowledge about where the different alternative crossing methods can meet local conditions on different crossing sites with regard to width and depth of the fjord, exposure to wind, sea waves, and ships traffic. © 2010 Elsevier Ltd. All rights reserved.

Vaa T.,Norwegian Public Roads Administration
19th Intelligent Transport Systems World Congress, ITS 2012 | Year: 2012

The NorSIKT project is carried out in cooperation between all Nordic countries (Sweden, Denmark, Island, Finland and Norway) and is financed by the NordFOU Research Cooperation (ministered by the Director Generals in each country). The main objective is to standardize the system for classification of motor vehicles in the Nordic countries. A state-ofthe-art report presents the situation in terms of current definitions for the classification of vehicles and describes the traffic counting systems in each country. The main principle in the classification system is to found the definition of vehicle categories on legal vehicle classification system in each country and use the main categories of vehicle types. Each country can adopt the classification properties that best meet the needs in the country. In the second and on-going phase different type of registration equipment and technologies is being tested to investigate how different type of equipment meets different classification principles. Preliminary results supports the need for further research to find out what type of technology and instrumentation that meets with the requirements for satisfactory accurate classification of vehicles. One should also look into the possibilities for creating an international standard procedure for testing and approval of traffic registration equipment.

Fransplass H.,Norwegian Public Roads Administration | Fransplass H.,Norwegian University of Science and Technology | Langseth M.,Norwegian University of Science and Technology | Hopperstad O.S.,Norwegian University of Science and Technology
International Journal of Impact Engineering | Year: 2013

The tensile behaviour of threaded steel fasteners is investigated numerically at elevated rates of strain using the finite element code LS-DYNA. A two-dimensional axisymmetric non-linear finite element model, adopting a thermoelastic-thermoviscoplastic constitutive model and a ductile fracture criterion, is used to predict the behaviour of the threaded steel fasteners. The material parameters are identified from inverse modelling using data from an experimental study previously published by the authors. The finite element model of the threaded assemblies, representing previously published tests, is used to predict the behaviour during loading at elevated rates of deformation, and, in particular, to determine the maximum load and the failure mode observed during testing. Based on the experimental parametric range the finite element model is capable of representing the experimentally observed failure modes and the measured load-deformation curves with good accuracy. The validated finite element model is also used to study how the behaviour of the assembly is affected by the test geometry, the grip length and the thermal softening. It is found that the threaded assembly represents with reasonable accuracy the behaviour of a real bolt-nut connection. Furthermore, it was found that the number of threads in the grip length could change the failure mode for the same loading rate and length of the thread engagement, and that thermal softening due to adiabatic heating seems to have no effect on the maximum load of the threaded rod assembly. © 2012 Elsevier Ltd. All rights reserved.

Thakur V.,Norwegian Public Roads Administration
Geomechanics and Geoengineering | Year: 2011

The numerical challenges that arise in modelling shear bands in soft sensitive (SS) clays have not yet been fully resolved. Convincing and wellaccepted solutions have yet to be found. This paper presents some novel information related to the shear band phenomenon in SS clays. In this study, the hypothesis is that the generation and dissipation of excess pore pressure from shear bands could regularise the strain softening and result in a mesh independent shear band thickness. The generation and dissipation of excess pressure is modelled by a coupled consolidation process. The simulation aims at modelling two counteracting mechanisms in the SS clay. First, the shear band narrows because of strain softening. Second, the internal pore water pressure drainage reduces the rate of strain softening. This counteracting mechanism provides an inherent regularisation technique for SS clays. This study presents some numerical results involving these two counteracting mechanisms. This study also shows that an inherent internal parameter applicable for SS clays can be defined by the ratio between soil permeability and the applied strain rate. In the case of SS clays, the range of this parameter varies from 0 to 0.0002 mm. © 2011 Taylor & Francis.

Vaa T.,Norwegian Public Roads Administration
20th ITS World Congress Tokyo 2013 | Year: 2013

There is a growing consensus internationally that ITS applications have a great potential to make winter operations more targeted and cost-effective and help to reduce the risk for accidents more in general. Real-time monitoring of the road state will be basic data both in a decision support system and in a warning system for the motorist especially in winter time. To monitor the prevailing driving conditions, remote sensing of road surface conditions is an interesting concept and throughout the last years there has come up some new products on the market. Even if there exists some documentation there is still a need for more testing and experience especially with mobile use of optic sensors under winter conditions and with an operational perspective. This is why it is taken an initiative in Norway to carry out a project on remote sensing of the road state by use of mobile units.

News Article | November 30, 2016
Site: phys.org

According to Statistics Norway, more than 2,600,000 private cars were registered in Norway last year. A very recent SINTEF report reveals that greenhouse gas emissions could be reduced corresponding to at least 100,000 of these vehicles by adopting the ISA ( Intelligent Speed Adaptation) system. "Our research shows that ISA is a really good way of persuading Norwegian motorists to reduce speed, and thus eliminate a large numbe of the most serious road accidents. It would also reduce greenhouse gas emissions and cut fuel consumption by at least 3.8 per cent," says SINTEF Senior adviser Terje Moen. Previous studies have shown that the system can help reduce the number of fatalities and serious injuries on Norwegian roads by 12 per cent. ISA, or Intelligent Speed Adaptation, is a system that monitors local speed limits and helps drivers to observe them. The system can be operated in three different modes: In the research project, the researchers used the advisory mode with auditory and visual display when motorists were driving too fast. GPS was used to determine the position of the vehicle, and the local speed limit was obtained from the National Highways Databank (NVDB). The display indicated the speed limit, and it flashed when this was exceeded. Sound was used to emphasise the warning when the speed limit (the ISA speed limit) was exceeded by four km/h or more," explains Mohn. If the system had been used in one of the other two modes, it would probably have had an even greater effect. SINTEF has drawn up the report on behalf of the Norwegian Public Roads Administration. The researchers took the data used in the study, which lasted for three years between 2011 and 2014, from ISA systems that were installed in 440 of the Public Roads Administration's own cars. During the first month of the study, the system was only used to study the driving patterns of the staff; i.e. neither the graphic display nor the sound signal was used. All the drivers were warned in advance that their driving would be monitored. Thereafter, the ISA was activated, and for the next 33 months data were logged in order to document the effect of ISA on speeds, fuel consumption and greenhouse gas emissions. ISA has a positive effect on speeding, i.e. the amount of time spent driving above the ISA speed limit. This was reduced from 5.9 to 3.4 per cent, or approximately 2.5 per cent. Fuel consumption and emissions were also both reduced. The SINTEF researcher believes that the difference would have been even greater if the drivers had not known that their driving behaviour was being monitored during the first month, before the ISA system was activated. "This may have encouraged our drivers to drive more slowly than they normally would have done. But the significant positive effect on typical speeds that we found when ISA was activated suggests that our results are robust, and are probably underrated rather than exaggerated," says Moen. One of the most effective systems Arild Ragnøy, a chief engineer with the Norwegian Public Roads Administration, says that ISA is one of the most effective speed control systems available. "The results of the SINTEF report show that ISA would probably have a positive effect on the number of accidents caused by excessive speed under given conditions," concludes Ragnøy. "Forced ISA is easiest to measure, since it is a simple matter to eliminate all the accidents caused by driving faster than the speed limit. A study carried out by the Institute of Transport Economics showed that 12 per cent of all fatalities and serious injuries on Norwegian roads could have been avoided if all private cars used ISA. This figure would have been lower using ISA's advisory mode, but there would still have been an effect," emphasises Ragnøy. The development of ISA started at the end of the 90s, and the system has been tested in several European countries since the turn of the century. "The system has proved to be very effective, but the question is whether people will accept their car overriding their desire to drive too fast. I can't imagine a politician daring to adopt compulsory use of ISA in all the cars in the country, even though the system has the potential to eliminate all speeding behaviour," says Moen. However, the SINTEF researcher believes that the system can be a useful aid for law-abiding motorists who want to avoid driving too fast. Many people find that driving with ISA is a pleasant experience, particularly on stretches of road where the speed limit changes frequently. And in the transport industry, the system could help to reduce stress in drivers who feel obliged to drive too fast in order to keep to timetables, whether they are driving buses or delivery vans. ISA could thus be a good means of satisfying HSE requirements for companies that are keen to do so. Transport industry customers can also be encouraged to buy transport services from companies that can document that they observe speed limits. Explore further: Drivers go faster than what they think is safe in roadworks zones

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