Showing papers on "Deck published in 2013"
TL;DR: In this paper, a composite bridge deck system that consists of an orthotropic steel deck stiffened with a 45mm reactive powder concrete (RPC) layer was proposed to enhance the stiffness of the bridge deck to reduce the fatigue stress amplitude.
Abstract: Fatigue damage in a conventional orthotropic steel bridge deck system poses a formidable challenge to bridge engineers all over the world because of ever-increasing heavy traffic volumes and higher wheel loads over the past decade. An effective solution may be to enhance the stiffness of the bridge deck to reduce the fatigue stress amplitude of its components. This paper proposes an innovative composite bridge deck system that consists of an orthotropic steel deck stiffened with a 45-mm reactive powder concrete (RPC) layer. Based on the analysis of HuMen Bridge in China (a suspension bridge with a conventional orthotropic steel bridge deck system with span length of 888 m) and two types of full-scale model tests, a comparison investigation is conducted between a conventional orthotropic deck system where the asphalt wearing course has been ignored and the proposed orthotropic deck system that includes an integral concrete wearing course, and the proposed composite bridge deck system proves to be considerably effective in reducing the stress range caused by service vehicle loads when applied to long-span steel suspension bridges. The thin RPC layer can be reliably integrated with the deck plate through stud shear connectors, and no shrinkage cracking occurs on the surface of the RPC layer that is cast on the deck plate. The fact that the tensile stress of the RPC layer is up to 42.7 MPa before cracking occurs demonstrates that cracking will not appear in the RPC layer under service vehicle loads. The analysis, which is investigated on the premise that the dead load weight of the bridge deck of HuMen Bridge is approximately the same for the two different deck systems, demonstrates that the stress of the orthotropic steel deck is significantly reduced with the application of the proposed composite deck system. Analysis with a three-dimensional finite-element model indicates that the transverse tensile stress of the deck plate is reduced by 71%, while that of the connection between the deck plate and the longitudinal troughs is reduced by 72%. This indicates that the risk of causing fatigue cracks in the steel bridge deck system can be considerably reduced during the entire life cycle of the bridge.
219 citations
TL;DR: In this paper, the authors present experiences and lessons from the structural health monitoring practice on the Tamar Bridge in Plymouth, UK, a 335m span suspension bridge opened in 1961, which was strengthened and widened in 2001 to meet a European Union Directive to carry heavy goods vehicles up to 40 tonnes by a process in which additional stay cables and cantilever decks were added and the composite deck was replaced with a lightweight orthotropic steel deck.
Abstract: This paper presents experiences and lessons from the structural health monitoring practice on the Tamar Bridge in Plymouth, UK, a 335-m span suspension bridge opened in 1961. After 40 years of operations, the bridge was strengthened and widened in 2001 to meet a European Union Directive to carry heavy goods vehicles up to 40 tonnes by a process in which additional stay cables and cantilever decks were added and the composite deck was replaced with a lightweight orthotropic steel deck. At that time, a structural monitoring system comprising wind, temperature, cable tension and deck level sensors was installed to monitor the bridge behaviour during and after the upgrading. In 2006 and 2009, respectively, a dynamic response monitoring system with real-time modal parameter identification and a robotic total station were added to provide a more complete picture of the bridge behaviour, and in 2006 a one-day ambient vibration survey of the bridge was carried out to characterize low-frequency vibration modes of the suspended structure. Practical aspects of the instrumentation, data processing and data management are discussed, and some key response observations are presented. The bridge is a surprisingly complex structure with a number of inter-linked load–response mechanisms evident, all of which have to be characterized as part of a long-term structural health monitoring exercise. Structural temperature leading to thermal expansion of the deck, main cables and additional stays is a major factor on global deformation, whereas vehicle loading and wind are usually secondary factors. Dynamic response levels and modal parameters show apparently complex relationships among themselves and with the quasi-static load and response. As well as the challenges of fusing and managing data from three distinct but parallel monitoring systems, there is a significant challenge in interpreting the load and response data firstly to diagnose the normal service behaviour and secondly to identify performance anomalies. Copyright © 2012 John Wiley & Sons, Ltd.
197 citations
TL;DR: In this paper, the authors presented the results of experimental and numerical investigation programs assessing the stress reduction in orthotropic steel bridge decks associated with ultra high performance fiber reinforced concrete (UHPFRC) topping layer.
129 citations
TL;DR: In this article, Wang et al. investigated the vortex-induced vertical force (VIVF) force on the flat closed-box deck of Xiangshan Harbor Bridge via wind tunnel tests of a spring-suspended sectional model at a large scale of 1/20.
92 citations
TL;DR: In this paper, a vortex-induced vibration (VIV) was observed in the upstream deck of a twin cable-supported bridge, which represents the first case of such an observation in an actual long-span cablesupported bridge.
83 citations
Patent•
8 Feb 2013TL;DR: In this article, a remotely integrated small-format aerial photography (SFAP) is used for bridge surface imaging and a deck condition rating technique based on large crack detection is used to quantify the condition of the existing bridge decks.
Abstract: Spatially Integrated Small-Format Aerial Photography (SFAP) is one aspect of the present invention. It is a low-cost solution for bridge surface imaging and is proposed as a remote bridge inspection technique to supplement current bridge visual inspection. Providing top-down views, the airplanes flying at about 1000 feet can allow visualization of sub-inch (large) cracks and joint openings on bridge decks or highway pavements. On board Global Positioning System (GPS) is used to help geo-reference images collected and facilitate damage detection. Image analysis is performed to identify structural defects such as cracking. A deck condition rating technique based on large crack detection is used to quantify the condition of the existing bridge decks.
77 citations
TL;DR: In this article, the influence of the container configuration on the deck of a ship on wind forces has been investigated through a series of wind tunnel tests with a 1:450 scale model.
71 citations
1 Jun 2013
TL;DR: In this paper, a full-depth precast, ultra-high-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementation of waffle decks were developed.
Abstract: As a part of an innovation project funded by the Federal Highway Administration (FHWA) Highways for LIFE program, a full-depth precast, ultra-high-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementation of waffle decks were developed. Following a successful full-scale validation test on a unit consisting of two panels with various types of connections under laboratory conditions, the waffle deck was installed successfully on a replacement bridge in Wapello County, Iowa. The subsequent load testing confirmed the desirable performance of the UHPC waffle deck bridge. Using the lessons from the completed project and outcomes from a series of simple and detailed finite element analyses of waffle decks, this report was developed to serve as a guide for broadening the design and installation of the UHPC waffle deck panel in new and existing bridges. Following an introduction to UHPC and waffle deck panels and a summary of completed work, this document presents information on waffle deck design, design of connections, redecking using waffle deck panels, and guidance on precast fabrication, construction, and installation of UHPC waffle deck panels.
68 citations
TL;DR: In this paper, an improved version of the band superposition approach is proposed, introducing a rheological model for high frequency unsteady forces, and the numerical model is validated against wind tunnel tests performed by means of an active turbulence generator and a multi-box deck sectional model.
65 citations
TL;DR: In this paper, a new concrete bridge deck cast onto glass fiber-reinforced polymer (GFRP) structural forms is studied, which replace the bottom layer of conventional rebar.
Abstract: A new concrete bridge deck cast onto glass fiber–reinforced polymer (GFRP) stay-in-place (SIP) structural forms is studied. The forms, which replace the bottom layer of conventional rebar, are essentially flat plates with T-up ribs. They span between support girders spaced at 1,772 mm and are lap-spliced using adhesive and mechanical fasteners. Special attention was given to the detailing of monolithic connections between the deck and girders to simulate continuity. The flange of the supporting concrete girders had a rough surface finish and protruded steel stirrups and mimicked AASHTO Type III girders. Five full-scale decks were tested to (1) compare the novel system with a conventional RC deck, (2) examine the effect of eliminating a top layer of orthogonal GFRP rebar, (3) assess a practice commonly used in bridge deck tests of using simple spans resting on neoprene pads, neglecting connection to girders, and (4) examine a commercially available all-GFRP deck, using the same GFRP panels but with...
48 citations
Patent•
4 Apr 2013
TL;DR: In this article, the authors propose an impact absorption mechanism operatively positioned at least in part between a deck and a base frame of the treadmill, which enables the deck to move relative to at least a portion of the base frame during impact events.
Abstract: A treadmill includes an impact absorption mechanism operatively positioned at least in part between a deck and a base frame of the treadmill so that the impact absorption mechanism enables the deck to move relative to at least a portion of the base frame during impact events on the deck and a selectively engageable deck stiffening mechanism that reduces the amount of movement of at least a portion of the deck relative to the base frame during impact events on the deck. The deck stiffening mechanism includes one or more generally rigid members and an engaging mechanism. The engaging mechanism selectively engages the one or more generally rigid members with the deck to provide support to the deck during impact events on the deck.
TL;DR: In this article, a spectral fatigue damage analysis of a double hull tanker structural detail accounting for corrosion wastage over time is presented, where the cyclic load of the wave-induced vertical bending moment, analysis using a strip theory on the frequency domain, is considered for two loading conditions.
Patent•
7 Nov 2013
TL;DR: In this paper, an offshore power generation structure comprising a submerged portion having a first deck consisting of an integral multi-stage evaporator system, a second deck portion comprising an integral multistage condensing system, and a third deck portion housing power generation equipment, cold water pipe; and a cold water connection.
Abstract: An offshore power generation structure comprising a submerged portion having a first deck portion comprising an integral multi-stage evaporator system, a second deck portion comprising an integral multi-stage condensing system, a third deck portion housing power generation equipment, cold water pipe; and a cold water pipe connection.
TL;DR: In this paper, three and four point bending fatigue tests were carried out on beam type specimens representing the reinforced deck and linear elastic simulations using FEA were performed to determine the stress distribution during tests.
Patent•
10 Dec 2013
TL;DR: In this article, a motorized or manual extendable and retractable floating device is supported longitudinally by one or more floatation devices, stored and supported by tracks or rails from beneath and between an upper deck of a houseboat, a tritoon boat, catamaran, floating dock, pier-supported dock or other watercraft or dock.
Abstract: A motorized or manual extendable and retractable floating device is supported longitudinally by one or more floatation devices. The flotation deck is stored and supported by tracks or rails from beneath and between an upper deck of a houseboat, pontoon boat, tritoon boat, catamaran, floating dock, pier-supported dock or other watercraft or dock. When fully extended, the floating deck will remain attached to the watercraft, and additional width may be achieved with extendable or fold out sides or wings.
TL;DR: In this article, the aerodynamic forces of a vehicle-bridge deck system under crosswinds in terms of aerodynamic coefficients were investigated and a relative velocity method was used to obtain the aerodynamics of a moving vehicle-deck system.
Abstract: To investigate the safety of road vehicles running on a long-span bridge under high crosswinds, the aerodynamic forces of a moving vehicle-bridge deck system need to be determined. This paper reports the use of computational fluid dynamics (CFD) to simulate the aerodynamic forces on coupled vehicle-bridge deck systems under crosswinds in terms of aerodynamic coefficients. The aerodynamic coefficients of a stationary vehicle-deck system were simulated and then compared with wind tunnel results. A relative velocity method was then used to obtain the aerodynamic forces of a moving vehicle-deck system. The moving effects on the aerodynamic forces on the vehicle-deck system were evaluated. The results show that the movement of the vehicle on the first lane of the bridge deck does affect the aerodynamic coefficients of the bridge deck but has only slight effects on the aerodynamic coefficients of the vehicle if the relative yaw angle to the vehicle is taken into account.
TL;DR: In this paper, a parametric study is presented in order to analyse the influence of design parameters on the construction of incrementally launched bridges in the construction stages, because static schemes vary continuously with the advance of the deck above the piers, for this reason temporary stresses in the deck, during launching, are rather different from those occurring in service life.
Patent•
15 Mar 2013
TL;DR: In this article, a personal vehicle system including a deck having a substantially flat top surface, where the top surface is substantially flat and is of sufficient area to support two feet of a user, and a truck coupled to the deck, consisting of a first portion coupled to a deck and a second portion that tilts relative to the first portion, was presented.
Abstract: A personal vehicle system including a deck having a substantially flat top surface, where the top surface is substantially flat and is of sufficient area to support two feet of a user, a truck coupled to the deck, where the truck consist of a first portion coupled to the deck and a second portion that tilts relative to the first portion, and a wheel motor coupled to the second portion of the truck. A personal vehicle system that includes a deck, a truck coupled to the deck, and a wheel motor coupled to the truck, where the wheel motor has a passive cooling system. The passive cooling system includes at least one endcap that rotates about a wheel rotation axis during operation of the wheel motor and the endcap has at least one fin.
TL;DR: In this article, the authors investigate the early age transverse cracking of bridge decks and evaluate the use of sealant materials, identifying suitable materials for crack sealing, with an ability to span cracks of various widths and to achieve performance criteria such as penetration depth, bond strength, and elongation.
Abstract: One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, and time dependent factors. The cracking of bridge decks not only creates unsightly aesthetic condition but also greatly reduces durability. It leads to a loss of functionality, loss of stiffness, and ultimately loss of structural safety. This investigation consists of field, laboratory, and analytical phases. The experimental and field testing investigate the early age transverse cracking of bridge decks and evaluate the use of sealant materials. The research identifies suitable materials, for crack sealing, with an ability to span cracks of various widths and to achieve performance criteria such as penetration depth, bond strength, and elongation. This paper also analytically examines the effect of a wide range of parameters on the development of cracking such as the number of spans, the span length, girder spacing, deck thickness, concrete compressive strength, dead load, hydration, temperature, shrinkage, and creep. The importance of each parameter is identified and then evaluated. Also, the AASHTO Standard Specification limits live-load deflections to L/800 for ordinary bridges and L/1000 for bridges in urban areas that are subject to pedestrian use. The deflection is found to be an important parameter to affect cracking. A set of recommendations to limit the transverse deck cracks in bridge decks is also presented.
TL;DR: In this article, an epoxy asphalt concrete protective course (EACPC) for the railway steel bridges is proposed, which has better strength performance and cracking resistance than the portland cement concrete (PCC), and the greatest bending strength is almost three times larger than that of PCC.
TL;DR: In this article, the authors developed a mathematical formulation for the aerodynamic analysis of offshore triceratops and examined its response under regular waves in the presence of wind, which showed significant reduction in deck response, with no transfer of rotation from the BLS; the deck remains horizontal under the encountered wave loads.
Abstract: The common types of deep-water offshore structures have rigid connections, resulting in more stresses on members subjected to environmental loads. On the contrary, the relatively new offshore triceratops alleviates the encountered environmental loads by virtue of its innovative structural form and design. The top deck and the buoyant leg structure (BLS) are connected to each other by universal joints that permit transfer of translations from the BLS to the top deck but restrain transfer of rotations. The present study develops a mathematical formulation for the aerodynamic analysis of offshore triceratops and examines its response under regular waves in the presence of wind. Based on the numerical studies conducted here, it is observed that triceratops shows significant reduction in deck response, with no transfer of rotation from the BLS; the deck remains horizontal under the encountered wave loads. Lateral displacement of the deck is restrained due to the compliancy offered by the ball joints. The heave...
Patent•
15 May 2013
TL;DR: In this article, a laminated treadmill deck or deck insert includes a wear surface formed of a phenolic impregnated paper laminated to an isocyanate resin bonded MDF core.
Abstract: A laminated treadmill deck or deck insert includes a wear surface formed of a phenolic impregnated paper laminated to an isocyanate resin bonded MDF core. A low moisture content isocyanate resin bonded wood fiber MDF core enables dimensional stability and high internal bonding strength even at reduced insert thicknesses. The deck or deck insert is disposed on a support deck adjacent the upper run of an endless treadmill belt. The deck or deck insert is provided with wear surfaces on each broad side and is easily removable and reversible to expose the second wear surface. The deck or deck insert is coated with as wax having fluoropolymer powder embedded in the exposed surface of the wax to provide a low-friction wear surface.
TL;DR: Topology optimization with the Solid Isotropic Material with Penalization (SIMP) method was used, and different shell structures with cavities for different values of given volume reduction were obtained, finding the most suitable pattern of cavities along the shell.
Abstract: A shell-supported footbridge was designed by shaping an anticlastic membrane in compression between deck and foundations. Since it would be subject to biaxial compression, it was appropriate to be ...
TL;DR: In this article, a fiber reinforced polymer (FRP) stay-in-place (SIP) structural formwork for concrete bridge decks was evaluated at a 1:2.75 scale and it was shown that as the width (w) is increased relative to span (s), the performance of the deck approaches the actual built performance.
TL;DR: In this article, a full-scale experimental investigation of the dynamic heat storage potential of the prefabricated hollow core deck elements with and without phase change material (PCM) and with or without increased bottom surface area of the decks is presented.
Patent•
22 Jul 2013
TL;DR: In this paper, a treadmill includes a support structure and a treadbase connected with a deck, and a continuous belt is trained around and rotatable about the front and rear pulleys.
Abstract: A treadmill includes a support structure and a treadbase connected thereto. The treadbase has first and second opposing side rails extending along at least a portion of first and second sides of the treadbase, respectively. A deck is connected to and between the first and second opposing side rails. Front and rear pulleys are connected to and between the first and second opposing side rails. A continuous belt is trained around and rotatable about the front and rear pulleys. One or more vibration assemblies are connected to the deck and selectively create vibrations to cause the deck to vibrate. The vibrations are transferred to a user during the performance of exercise to provide various physiological benefits to the user.
TL;DR: In this paper, the impact of surfacing on the response up to failure of orthotropic GFRP bridge decking local to concentrated loading was investigated. But, unlike real FRP deck bridges, no debonding was observed at the surfacing-deck interfaces during these tests.
Abstract: This paper presents experimental results which demonstrate the important, but to date little-studied influence of surfacing on the response up to failure of orthotropic GFRP bridge decking local to concentrated loading. Four bonded deck specimens were tested, two without surfacing and two including a 30 mm thick polymer concrete surfacing layer. A specified steel plate-rubber pad ensemble which produced a load distribution generating high shear and low moment locally was used to load one surfaced and one unsurfaced specimen to failure, while a plate-pad system inducing modest shear and high moment locally (nearer the tyre effect) was used to fail the other two specimens. The surfaced specimens' load capacities exceeded those of their unsurfaced counterparts by 90% and 261% under the shear-dominant and moment-dominant loads respectively. For each surfaced specimen, failure occurred in part by formation of a distinctly curved crack in the polymer concrete. In contrast to reports of detached surfacing on real FRP deck bridges, no debonding was observed at the surfacing-deck interfaces during these tests. This suggests scope for significantly improved surfacing-deck bond integrity in practice. GFRP delamination, particularly within the directly loaded flange, also occurred in the four test specimens. The critical failure zone shifted from the flange's ends to its local midspan in changing from shear-dominant to moment-dominant loading. It is concluded that the status quo standard of testing unsurfaced deck specimens should be modified to testing of surfacing-deck systems. (c) 2012 Elsevier Ltd. All rights reserved.
TL;DR: In this paper, the flexural capacity of an external reinforced concrete beam without concrete on the tension part (ECB) was investigated and an experimental flexural test was carried out.
TL;DR: In this article, a comprehensive mechanics framework has been developed, taking into account the critical deterioration rates of the composite panels of the FRP constituents, to simulate the long-term performance of FRP deck structures subject to the combined effects of mechanical and environmental loading.
Abstract: Fiber Reinforced Polymer (FRP) composite panels are particularly attractive as bridge decks due to their high strength, low density, and durability, which are of importance in the bridge industry. Although the short term performance of FRP decks is satisfactory, the long-term performance under weather conditions still awaits future testimony and remains a major concern in their use as primary load bearing members. Since the load capacity and structural stiffness of FRP decks deteriorate over time at different rates, it is necessary to develop robust mechanics models to simulate the long-term performance of FRP deck structures subject to the combined effects of mechanical and environmental loading. To this end, a comprehensive mechanics framework has been developed, taking into account the critical deterioration rates of the FRP constituents. Such deterioration relationships were obtained by calibrating the accelerated laboratory durability test data with the in-service field measurements. Simulation results agree well with the 4-year performance data of a FRP-deck road bridge. Long-term validation data is, however, still needed.
TL;DR: In this article, the authors report failure of hybrid members comprising cellular GFRP decking connected to RC beams via an epoxy adhesive and show that the adhesive is a significant deck-to-beam shear connector under positive and negative moments.
Abstract: This paper reports tests to failure of hybrid members comprising cellular GFRP decking connected to RC beams via an epoxy adhesive. RC beams of low crack widths under service loads are useful with GFRP decking owing to the economy of and modest expertise needed to install such beams. Key novelties of this investigation include the RC beams (steel, FRP and prestressed concrete beams have been used previously) with the GFRP decking, use of the epoxy-bonded (so chemical, an alternative to mechanical) connection between the GFRP decking and the concrete beams, and study of the positive and negative moment responses (for application to continuous bridges) of this hybrid form. The test results show the adhesive to be a significant deck-to-beam shear connector under positive and negative moments. Whether the deck was a tensile or compressive top chord, the primary failure mode, which occurred at high loads, was delamination within the GFRP at the deck’s flange-to-web joints, and was neither failure of the GFRP-adhesive interface nor of the adhesive between deck units. For the positive moment specimen there was also fracture of the concrete near the deck as observed for FRP-plated RC beams, despite the absence of flexural cracks from this near-deck concrete.