United States
United States

Time filter

Source Type

De La Paz Cobos E.,Ayuntamiento de Madrid | Alcaniz P.J.R.,MBA | Mazo C.S.O.,Catedratico de Ingenieria del Terreno | Gracian F.T.,Dragados
Revista de Obras Publicas | Year: 2013

The article describes the design and construction of the Arroyofresno Stormwater Deposit (the largest of its kind in Europe) and the associated pipework, a 7.40 m diameter tunnel built by EPB TBM. A description is given of the design criteria as well as the soil treatment required for the passing of the pipeline through a river, alongside various installations (in quaternary soils) and below motorways, as well as those necessary to connect the tunnel to the service wells.

Mari A.,Polytechnic University of Catalonia | Bairan J.,Polytechnic University of Catalonia | Moreno R.,Polytechnic University of Catalonia | Oller E.,Polytechnic University of Catalonia | Alvarez J.J.,Dragados
Bridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management | Year: 2012

Many bridges of the current roadway system need to be upgraded to accommodate them to new traffic, geometric or performance requirements. In order to ensure the required levels of serviceability and safety of the bridge, it is necessary to realistically evaluate its structural response before, during and after the intervention. In this paper, a sequential non-linear and time dependent analytical model, capable to reproduce the effects of the modifications needed to adapt the actual bridges to future needs, is presented. The model is applied to the analysis of an actually modified overcrossing in Spain, in which the intermediate piers had to be moved in order to increase the number of lanes of a freeway. Two alternative strengthening solutions are analysed and comparisons between the structure responses in both cases are made, showing the capabilities of the model as a helpful tool for designing efficient remodelling and strengthening solutions. © 2012 Taylor & Francis Group.

Moreno-Navarro F.,University of Granada | Sol-Sanchez M.,University of Granada | Rubio-Gamez M.C.,University of Granada | Segarra-Martinez M.,Dragados
Construction and Building Materials | Year: 2014

The high stiffness provided by high modulus asphalt mixes significantly decreases the loads transmitted by the traffic to the road foundation whilst at the same time increases their resistance against plastic deformations. Thus, the use of these types of mixtures can be an effective solution in road construction, due to the fact that they can reduce the thickness of the pavement, saving economic and material resources. Nevertheless, in some cases this high stiffness constitutes a drawback because it could reduce the fatigue resistance offered by these materials, leading to a premature appearance of cracks in the pavement, which decreases its service life. Due to this fact, the use of high modulus asphalt mixes is limited, especially in cold climates. In order to solve this problem, this research has been focused on the improvement of the mechanical performance of high modulus asphalt mixtures through the use of additives (crumb rubber and acrylic fibers), which could increase their fatigue resistance by maintaining the stiffness required. Different tests have been carried out under different temperatures for the mixtures assessment. The results obtained have shown that the incorporation of these additives could lead to a better mechanical behavior of high modulus asphalt mixes, and thus it could improve their performance. © 2014 Elsevier Ltd. All rights reserved.

Parrilla P.R.,Zona Cono Sur DRAGADOS | Espinoza J.,Besalco Construcciones | Palma A.,SRK Consulting Chile S.A. | Gonzalez E.F.,DRAGADOS
Revista de Obras Publicas | Year: 2012

In 2008 a new type of TBM system (Double Shield Compact) was developed for the excavation of tunnels in variable rock conditions. This type of TBM was selected to excavate the 8 km long exploration tunnel in Chile for Los Bronces mine, one of the largest copper mines in the world owned by Anglo American. The 4.5 m diameter tunnel runs at an elevation of 3.600 m a.s.l. and crosses a series of geological formations of hard, compact rock crossed by several faults. The restricted area for the tunnel entrance, the climate and the required flexibility in rock support design posed the main challenges for this project.

Fernandez E.,Dragados | Sauer G.,Dr Sauer Corporation
Proceedings - Rapid Excavation and Tunneling Conference | Year: 2013

Tunneling is one of the industry's solutions to improve our environment and consequently Quality of Life. Putting infrastructures and services underground definitely contributes to a more pleasant urban surface. But how to minimize its long-term construction impact and the "high risk/cost" myth? The authors are trying to identify preconceptions in this particular industry and offering more reliable approaches in terms of cost and schedule based on an overall control mechanism.

Vazquez M.,DRAGADOS | Negro V.,Technical University of Madrid | Lopez J.S.,Technical University of Madrid | Monso J.L.,Institute Hidrodinamica Aplicada INHA
Coasts, Marine Structures and Breakwaters 2013: From Sea to Shore - Meeting the Challenges of the Sea | Year: 2014

This paper presents a novel type of caisson as an integrating element in a new concept of vertical breakwater. The solution combines the advantages of cylindrical geometry with stepped wave energy dissipation, which results in a reduction of maximum wave forces, loads transmitted to foundations and a reduction in crest level in comparison with a conventional vertical breakwater. Also, substantially less materials are used. Whilst the system is complex and depends on multiple geometric, hydraulic, construction and economic variables, this article centres on its hydrodynamic aspects and summarises the most important results of a reduced model testing programme with regular wave action in the first instance, as undertaken to validate the solution in a general fashion.

Fernandez E.,Dragados SA | Magro J.L.,Dragados | Sanz A.,Dragados
Proceedings - Rapid Excavation and Tunneling Conference | Year: 2011

The WSDOT has decided to replace the old Alaskan Way Viaduct on the SR99 for a single bore tunnel able to allocate two lanes on each direction. In accordance with the ground conditions existing on Seattle a pressurized TBM is the right choice. But, the required 57.4′ on excavation diameter goes by far, beyond the existing TBM's and will require the application of the newest technologies on its development. To succeed on this bid a careful and documented technical approach was made, evaluating first the two options between slurry and EPB to excavate the tunnel, followed by the selection of the most effective and proved systems and devices, sometimes duplicated, in order to build the perfect machine for the biggest TBM tunnel ever built, till now. Not only the TBM, but also the impact of the new urban tunnel on the surroundings must be deeply considered during the bid stage in order to estimate the cost and schedule of the ground treatments required to minimize the volume loss and consequently to progress with the excavation in the safest way for all the parties (see Figure 1).

Acerete A.,Acciona | Ayala J.,Acciona | Pidal G.M.,Dragados | Peset L.,Dragados
Structural Engineering International: Journal of the International Association for Bridge and Structural Engineering (IABSE) | Year: 2014

The bridge over the Beauharnois Canal (BHC) is the main structure of the Nouvelle Autoroute 30 project, with a total length of 2551 m. It crosses the BHC and the Saint Laurent Seaway (SLS). This paper describes the development of the design and construction process of the Beauharnois Bridge carried out by a leading construction company in Montreal. It describes the construction procedures carried out to achieve the works in a schedule severely limited by the technical clauses of the contract and winter conditions. This paper emphasizes the different prefabrication systems employed in the construction of the bridge and the incremental launching technique used to erect the steel box-girders of the east part over the BHC and the SLS. The bridge superstructure is divided into two parts: the east part, formed by a closed composite structure with a steel box-girder spanning over 82 m, and the west part, designed with a concrete deck composed of five concrete prefabricated beams spanning a typical length of 45 m. The east part, with a length of 1456 m, was designed with no expansion joints. This side of the deck includes the main span of 150 m and was entirely assembled at the east abutment and erected in place using the incremental launching technique.

Segarra Martinez M.J.,Dragados
Revista de Obras Publicas | Year: 2014

The article describes the particular characteristics of the construction industry with regards to the development of R&D&l activities and the introduction of innovation in the market, when taken from the perspective of the Dragados construction company and, by extension, that of possibly most other large building contractors. A description is given of the context in which these activities are earned in the construction industry and the means by which large contractors approach the problems entailed in the management of R&D&l activities. The article provides a brief summary of certain initiatives that ensure or help ensure that innovation in construction reaches the market to the widest extent possible and concludes with a number of examples of R&D&l activities earned out at Dragados.

Fernandez E.,DRAGADOS | Sanz A.,DRAGADOS
Underground - The Way to the Future: Proceedings of the World Tunnel Congress, WTC 2013 | Year: 2013

The replacement of the old Alaskan Way Viaduct on the SR99 for a single bore tunnel able to allocate two lanes on each direction is the right way to improve the quality of life of Seattle's citizens. For that purpose, an EPB 17.5 m diameter has been selected to excavate the tunnel which is expected to start on spring 2013. The Japanese manufacturer Hitachi Zosen is building the machine which is fitted with proven technologies able to deal with the most varied geologies expected along the alignment. A free air intervention to revise and repair the cutting tools is the most innovative solution on western tunnels despite it has being applied in Japan for more than 12 years. Also robotized segment erector is the logical approach on these large size TBM's. But the Seattle solution can be exported to other cities to solve similar problems and must go together with new TBM developments. The paper describes the latest technologies applied in Seattle and revises alternatives for road and multipurpose tunnels. © 2013 Taylor & Francis Group.

Loading Dragados collaborators
Loading Dragados collaborators