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Investigation of the structural system conversion under transverse wind load based on the long-term monitoring lateral response of Sutong Bridge
Published in Hiroshi Yokota, Dan M. Frangopol, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 2021
Sutong Bridge, designed as a semi-floating system, is unique compared with other long-span cable-stayed bridges. The lateral displacement of the steel girder is constrained at the near-pylon auxiliary piers (A.P.) and transition piers (T.P.) by two kinds of spherical steel bearings, as depicted in Figure 10. Besides, there are two transverse wind-resistant bearings located between the girder and each pylon (Figure 11(a)). It can ensure the steel girder and the pylon contact properly, and control the horizontal displacement of the girder in the situation of strong wind. The bearings are mainly composed of two parts (Figure 11(b)). One part contains the support system and it is fixed to the steel box girder by connection bolts, while the other part is a smooth steel slipway, which is embedded in the corresponding position of the concrete pylon. The two parts are connected by a cylindrical sleeve. The unique feature of this bearing is that there is a certain gap inside the sleeve between the support system and pylon, which means that the bearing does not contact the pylon normally. Meanwhile, the sleeve and the support part can slide with the main girder on the slipway to ensure that the longitudinal freedom of the girder is not affected by this bearing.
Analysis of SME Ship Repair Yard Capacity in Building New Ships
Published in C. Guedes Soares, T.A. Santos, Progress in Maritime Technology and Engineering, 2018
I. Atanasova, T. Damyanliev, P. Georgiev, Y. Garbatov
The ship assembly will be performed on the eastern building berth. The required equipment is shown in Table 4. At this production stage, the following processes should be carried out:placing/positioning of the building berth support-slipway cars;positioning and aligning of blocks—ship hull blocks are assembled consecutively;hull blocks are welded;mounting of the main engine;fitting of gears and installations;hull testing before launching;painting;positioning on a dock and launching afloat.
Tunnel construction techniques
Published in David Chapman, Nicole Metje, Alfred Stärk, Introduction to Tunnel Construction, 2017
David Chapman, Nicole Metje, Alfred Stärk
Steel shell immersed tube tunnels can be built using either a single- or double-shell construction. In a single-shell construction, there is actually an internal concrete lining and an outer steel shell plate that has been stiffened internally. This outer steel shell acts as a permanent watertight membrane, as the formwork for the internal concrete lining and as the structural element to carry the flexural forces before and after placement. In the double-shell construction, there is an additional outer steel shell. The area between the two steel shells provides a convenient space for additional ballast. The steel structure and part of the concrete is normally constructed at a shipyard, either in a dry dock or launched from a slipway. Unlike concrete elements which are sensitive to settlement, shrinkage and creep effects, steel shelled elements have sufficient flexibility and ductility so that these features do not control the design. However, the structural analysis of a steel element must consider each stage of construction separately: fabrication and launching, outfitting and in situ loading.
Does end-of-life ships research trends change in last three decades? A review for the future roadmap
Published in Journal of International Maritime Safety, Environmental Affairs, and Shipping, 2023
Bisma Mannan, Md Jahir Rizvi, Yong Ming Dai
The slipway technique, as shown in Figure 2, is a non-tidal beaching method that is an alteration of the beaching technique (LR, 2011; Mikelis, 2018). The tidal difference is the key distinction between the slipway and the beaching technique. It is performed in regions that have low tidal differences, particularly in Turkey (Hougee, 2013). Additional to Turkey, the slipway method is exercised in several historic ships dismantling sites, for instance, Inverkeithing in the UK (K. P. Jain & Pruyn, 2017; LR, 2011). In the US, slipways are mostly 100–120 ft wide and 400–700 ft long at the opening (USEPA, 2000). According to (Mikelis, 2013a), around 4% of the ship recycling facility utilizes the slipway approach for ship dismantling. Furthermore, with this procedure, the commercial vessel is dragged either far up the coast or on a slipway built of concrete running to the ocean, and due to the absence of tides, some hazard control is possible. This implies that many incidental spills can fairly be covered, and the elevating and retrieving procedure takes place at a relatively stable and predictable harbour (K. P. Jain & Pruyn, 2017; LR, 2011). Generally, the machinery pieces and hull are separated from the shipping vessel with the help of a winch running from the seashore. It is often assumed that a little tidal difference will enhance accessibility to the hull. In comparison to beaching, the slipway operating area provides advantages for reliable operations (Hougee, 2013).
A fuzzy best–worst method (BWM) to assess the potential environmental impacts of the process of ship recycling
Published in Maritime Policy & Management, 2022
Omer Soner, Erkan Celik, Emre Akyuz
The environmental impacts of the recycling process are assessed by utilising the Fuzzy BWM in this section. While increasing ship recycling (either executing at slipway, beaching, dry dock or alongside) events provide positive impacts on the economy, the results of the process could possibly damage the environment. The execution of the Safe and Environmentally Sound Recycling regulations of Ships addresses some concerns raised about the environmentally hazardous substances. On the other hand, the real applications of various facilities are especially still a gap. While many areas of the ship recycling have been closely investigated, the number and variety of studies devoted to the environmental effects of the recycling process has been limited. The list of possible hazards, their consequences and environmental impacts are presented in Table 2. Details of the table have been gathered from comprehensive literature reviewing associated with ship hazards and environmental impacts of ship recycling process, circulars, and resolutions introduced by IMO and Lloyd Registers. In particular, guidelines for the development of the inventory of hazardous materials, which were prepared by MEPC (Marine Environment Protection Committee), were to provide ship-specific information on the actual hazardous materials present on-board.
Dry-docking performance measurement model – multi criteria non parametric approach
Published in Ships and Offshore Structures, 2021
Denis Rabar, Duško Pavletić, Sandro Doboviček, Maja Vlatković
The DEA methodology is adjusted for the dry-docking performance measurement to be applied on the population of 34 vessels in total, in order to create a functional dry-docking performance measurement model. The vessels have been built on the same basic technology, i.e. erected on slipway, longitudinally launched, finally outfitted and commissioned while afloat on the outfitting pier, seaworthy for transfer to dry-dock. The gross tonnage (GT) for the vessels covered in this paper ranges from 8500 up to 47,300. The dry-dockings have been carried out in five different repair shipyards, four of them within one-day steaming distance from the newbuilding shipyard, and one repair shipyard three days steaming away. The surveyed population consists of 19 RO-RO type vessels and 13 Chemical Tanker (CT) type vessels, and two more Hopper Dredgers. The DEA newbuilding dry-docking performance measuring model is presented in Figure 1, in block diagram form, describing the data collection, inputs and outputs setting, choosing the DEA model orientation, carrying out the preliminary and the final calculations, analyzing results and coming up with the source of inefficiency recognition, conclusions and recommendations for the process improvements and future decisions.