Abstract: A new steel orthotropic deck was installed on the Bronx–Whitestone Bridge (BWB) between 2005 and 2006. In May 2007, longitudinal cracks were found by visual inspections underneath the deck plate in the rib-to-deck welds and have continued to occur. As of 2014, these rib-to-deck weld cracks have required weld repair of approximately 305 m (1,000 ft) of the 65,374 m (214,480 ft) of rib welds in the new orthotropic deck. Detectable cracks have occurred randomly in 66 of the 408 shop-fabricated deck panels. This paper’s focus is on modeling the crack propagation of the defective welds with fabrication-related hot cracks so that estimates of the possible cracking from these fabrication defects can be predicted. Creation of this model also involved considering truck traffic using the structure and the wheel paths along with the supporting ribs most likely to experience stress cycles during service.

Abstract: An innovative lightweight composite deck (LWCD) is proposed for steel bridges to avoid premature fatigue cracking. The composite deck is composed of an open-ribbed orthotropic steel deck (OSD) and a thin ultrahigh-performance concrete (UHPC) layer. This study is based on a suspension steel bridge in China, namely, the Second Dongting Lake Bridge. The following investigations were performed: (1) preliminary finite-element analysis (FEA) was carried out to evaluate the vehicle-induced stress ranges (i.e., Δσ = σmax − σmin) of six typical fatigue-prone details; (2) parameter analyses were performed to investigate the effects of the shape of cutouts and the thickness of the floor beams; and (3) two fatigue tests, one that used a full-scale LWCD panel and another that used a LWCD beam specimen, were conducted to reveal fatigue performance of the OSD and the stud shear connectors, respectively. Results of the preliminary FEA show that, with the contribution of the UHPC layer, the vehicle-induced stress ranges at some fatigue details of the LWCD, such as the rib–deck plate welded joints and the splice welds of the longitudinal ribs, were reduced to be less than their constant-amplitude fatigue limits, which indicates theoretically infinite fatigue lives of these details. The parameter analyses reveal that the apple-shaped cutout had relative good fatigue properties among the four cutout schemes and that the thickness of the floor beams is recommended to be 14–18 mm. According to the fatigue tests on the composite panel specimen and on the composite beam specimen, both the open-ribbed OSD and the stud shear connectors exhibited satisfactory fatigue endurances, which were much greater than 2 million cycles. The current theoretical and experimental investigations reveal that the proposed open-ribbed LWCD has favorable fatigue performances.

Abstract: Recent natural extreme events, such as Hurricane Ike in the U.S. (2008), Tohoku tsunami in Japan (2011), and Typhoon Haiyan in Southeast Asia (2013), have caused significant damage to the decks of coastal bridges. The failure of the structure occurs when wave-induced loads on the decks of coastal bridges exceed the bridge capacity, resulting in partial removal or a complete collapse of bridge decks. Tsunami, storm waves, and storm surge are known to be the ultimate agents of such failures. An understanding of the failure mechanism and possible solutions require a better knowledge of the destructive loads on the structure. Interaction of surface waves with the bridge deck is a complex problem, involving fluid–structure interaction, wave breaking, and overtopping. Possible submergence of the deck and entrapment of air pockets between girders can increase destructive forces and add to the complexities of the problem. In recent years, remarkable progress has been made on this topic, resulting in some new findings about the failure mechanism and the destructive wave loads. A review of the key studies on wave loads on the coastal bridge decks, including those in the past and very recently, is presented here. Emphasis is given to the pioneering works that have significantly improved our understanding of the problem. Challenges associated with the existing solutions are highlighted, and suggestions for future studies are provided.

Abstract: The widely used orthotropic steel deck system is subject to several durability problems: fatigue cracking of the steel, wearing of the surfacing, and corrosion. Thus, the composite deck system composed of an orthotropic steel deck and an ultrathin reactive-powder concrete (RPC) layer was proposed. In a prefabricated composite deck system, joints formed between the prefabricated RPC layer and the cast-in-situ RPC layer are defined as wet joints. The experimental study was conducted on the tensile behavior of RPC wet joints to ensure the integrity of the prefabricated deck system and the serviceability and durability of the RPC layer. Two series of tests were conducted, including seven tensile tests on panels and four negative bending tests on beams. In these tests, five types of new wet joint details were designed in addition to the integral casting detail and the conventional wet joint with a vertical, plane interface. To study the mechanical properties and crack resistance performance of differen...

Abstract: A computational fluid dynamics–based numerical parametric study for the characteristics of the solitary wave–induced forces on typical coastal twin bridge decks is conducted in this study. At first, the second-order solitary-wave model is developed followed by a verification process with the analytical one and a related experimental study. The laminar flow model and shear stress transport (SST) k-ω model are adopted and the comparisons of their results demonstrate that they can make close predictions for the bridge deck forces. Then, the general characteristics of the wave forces for a fixed deck gap and variable deck gaps with different still water levels (SWLs) and various submersion coefficients are observed. In addition, the characteristics of the wave forces on the landward bridge deck are presented by normalized factors based on the wave forces on the seaward deck. Finally, the hydrodynamic interference effects between the twin bridge decks are investigated and the effects of the deck vibrat...

Abstract: Wearing surfaces are integral parts for long-span orthotropic steel deck bridges and well-designed wearing surfaces will be able to carry the traffic crossing the bridge smoothly and maintain the operation of the bridge. However, until now a systematic procedure has still been necessary for designing such wearing surfaces. In this paper, an integrated procedure is proposed for designing the epoxy asphalt concrete (EAC)–based wearing surfaces. The proposed design procedure includes five major steps: data collection and preparation, epoxy asphalt concrete design, structure design, tolerance determination, and empirical validation. The design details for each step are described accordingly. In a case study, the proposed design procedure is demonstrated through applying this procedure on designing the wearing surface for the Second Nanjing Yangtze River Bridge located in Nanjing City, China. The case study results show that the proposed procedure can be applied to design a feasible wearing surface sys...

Abstract: This article describes the research work relating to the assessment and control of human-induced vibration of an unusual curved cable-stayed bridge with separate road and pedestrian decks. Dynamic simulations of human-induced vibration were performed with a mode-by-mode approach, and the results showed that a total of eight lateral and vertical modes of the bridge may suffer from excessive vibrations at the design crowd density. A hybrid control scheme was developed for control of human-induced vibration, which consists of steel braces fitted between the road bridge deck and the pedestrian deck to improve structural stiffness and eddy current tuned mass dampers to enhance damping ratios of lively modes. The modal properties of the bridge with steel braces were experimentally obtained by dynamic tests and used for parameter tuning of mass dampers. The performance of the hybrid control strategy was evaluated by group tests of up to 400 pedestrians. It is shown that the critical number of pedestrians...

Abstract: Compact reinforced reactive powder concrete (CRRPC) was proposed to retrofit deteriorated asphalt overlays and to strengthen orthotropic steel deck (OSD) bridges. The resultant OSD-CRRPC composite deck is also referred to as a light-weight composite deck (LWCD) system. This paper provides experiences and lessons learned from the first application of CRRPC to retrofit the deficient asphalt overlay of an existing steel bridge in China. The paper includes information relating to finite element (FE) model analyses, a fatigue loading test, construction processes and a field measurement. FE analyses revealed that a 50-mm CRRPC layer decreased the vehicle-induced stresses in the OSD by 34–83% relative to an OSD with an 80-mm asphalt overlay. As a result, the fatigue life of the OSD could be extended significantly. The static and fatigue safeties of CRRPC were proved by comparing the predicted and experimental stresses, and field construction demonstrated the feasibility of the proposed system. CRRPC developed no...

Abstract: Epoxy asphalt concrete is widely used for long-span steel bridge deck pavement in China. Because of the heavy traffic load and extreme climatic conditions, epoxy asphalt deck pavement tends to develop cracks, debonding, and potholes and needs reconstructing typically after 5 to 10 years. Research was performed on the cracking mechanism under both traffic and thermal loads, with the aim of finding the best sealing material. The performances of various crack-sealing materials, including workability, mechanical property, and durability, were evaluated. Test methods such as the simplified penetration ability test and bending fatigue test were employed for rating the crack-sealing materials. Experimental results revealed that the traditional crack-sealing materials, such as bitumen modified with styrene–butadiene–styrene, rubber bitumen, bitumen emulsion, and solvent bitumen, cannot meet the requirements for repairing epoxy asphalt on long-span bridge decks because of the low penetration ability and low adhesi...

Abstract: Advances in fiber-reinforced polymer (FRP) technology have led to the introduction of new basalt-fiber-reinforced-polymer (BFRP) bars. This paper presents a research project investigating the behavior of edge-restrained concrete bridge-deck slabs reinforced with BFRP bars. The tests included six full-scale edge-restrained concrete deck slabs simulating a slab-on-girder bridge deck commonly used in North America and one full-scale unrestrained concrete deck slab. The deck slabs measured 3,000 mm long × 2,500 mm wide × 200 mm thick. The test parameters investigated were (1) reinforcement type (BFRP and steel); (2) BFRP bar size (12 and 16 mm); (3) reinforcement ratio in each direction (0.4–1.2%); and (4) edge-restraining [restrained or unrestrained (free)].The slabs were tested up to failure over a center-to-center span of 2,000 mm under a single concentrated load acting on the center of each slab over a contact area of 600 × 250 mm to simulate the footprint of a sustained truck wheel load (87.5-kN ...

Abstract: Horizontally curved bridges have been observed to suffer severe structural damage during past earthquakes. Unseating of the deck from abutments is one of the typical modes of failure of horizontal curved bridges. This type of failure is caused primarily because of excessive in-plane rigid-body motion of decks of these bridges, mainly due to the irregular geometry of the bridge itself and seismic pounding between the deck and abutments. This paper investigates the influence of seismic pounding on rigid-body motion of horizontally curved bridges during strong earthquakes using an analytical approach. For this purpose, a 3-degree-of-freedom nonlinear model has been developed to capture main dynamic parameters affecting seismic response of horizontally curved bridges. The accuracy of this model has been verified by finite-element modeling of a typical horizontal curved bridge. An extensive parametric analysis has been performed by varying key parameters, including the size of the gap between the deck ...

Abstract: The steel bridge deck overlay provides a smooth surface for riding and protects the deck from influence of traffic and environment factors. The presence of distress on overlay may compromise the serviceability of a bridge. A better understanding of distress is indispensable for designers to make improvements on asphalt overlay to extend the service life. A field investigation into performance of two bridge deck asphalt overlay systems was conducted. The overlay system included an epoxy asphalt overlay and a composite asphalt overlay consisting of Stone-Matrix-Asphalt (SMA) and Gussasphalt (GA). The field investigation was conducted to evaluate the difference in performance between two systems. Chemical analyses were performed on core samples from each bridge to further investigate the distress mechanism of each system. Results indicated that the two overlay systems generally exhibited similar field performance. Each bridge developed different distress, mainly due to the poor bonding between layers or between overlay and steel deck.

Abstract: Cracking is a major distress in steel bridge deck pavements. To determine the critical cracking zone, a numerical multiscale structural analysis was proposed and performed on the basis of a case study. First, a whole bridge model was analyzed, which revealed that the critical segment under critical load combination was one-fourth of the bridge span. Second, the critical segment was modeled using the finite mixed element method, and the critical local plate was determined. Third, using a submodel technique, the critical orthotropic steel plate with pavement was analyzed. The constructed model was then updated through an equivalent impact factor obtained from a numerical model analysis that considered vehicle–pavement interaction. From such multiscale model analysis, the crack distribution law of steel deck pavements was determined. Comparison of the analysis results from a traditional model with the multiscale model revealed the non-negligible effects of bridge structure and pavement evenness. Find...

Abstract: In this work, the dynamic response of a cable-stayed bridge that consists of a simply supported four-cable-stayed deck beam and two rigid towers, subjected to a moving vehicle load, is studied. The vehicle is modeled as a mass–spring–damper system moving at a constant velocity, which is assumed to keep contact with the deck beam at all times. Convective velocity and acceleration terms associated with the moving vehicle as it traverses along the vibrating deck beam are taken into consideration, as well as geometric nonlinearities of stay cables. The nonlinear response of the cable-stayed bridge is obtained by solving nonlinear and linear partial differential equations which govern transverse and longitudinal vibrations of stay cables and transverse vibrations of segments of the deck beam, respectively, along with their boundary and matching conditions. Orthogonality relations of exact mode shapes of the linearized undamped cable-stayed bridge model are employed to convert the coupled nonlinear partial differential equations of the original nonlinear cable-stayed bridge model to a set of ordinary differential equations by using the Galerkin method. The dynamic response of the cable-stayed bridge is calculated using the Runge–Kutta–Fehlberg method in MATLAB. Convergence of the dynamic response from the Galerkin method is investigated for two cases in which the velocities or masses of the moving vehicle are different. Results show that an accurate calculation of the dynamic response of the cable-stayed bridge needs use of a large number of modes of the linearized undamped cable-stayed bridge model, and needs many more modes for the deck beam than stay cables. Moreover, effects of the velocity and mass of the moving vehicle and the convective terms on the dynamic response of the cable-stayed bridge are studied with convergent Galerkin truncation.

Abstract: A novel deck system is developed as an ultralightweight low profile waffle slab of ultrahigh-performance concrete (UHPC) reinforced with carbon-fiber-reinforced polymer (CFRP) bars. The proposed system lends itself to accelerated bridge construction, and has great potential for deck replacement in bridges with load restrictions, and as well for bridge widening. A total of seven specimens at two different overall depths, with single or multiple ribs and in simple or two-span configuration, were tested in two consecutive phases in this study. The results were compared to similar deck panels with high-strength steel (HSS) reinforcement from previous studies. The study confirmed that the proposed deck panel with only 102 mm overall depth and a self-weight of 0.9 kN/m2 meets the demand for a 1,219-mm stringer spacing. The flexural behavior and failure modes of the deck are in general similar to the UHPC-HSS deck. The deck is not susceptible to punching shear of its thin slab and fails in a ductile man...

Abstract: A 142-m, three-span continuous footbridge over the Esino River (Italy) is considered as a case study to illustrate a number of challenging aspects in its static and dynamic design. The adoption of an optimized steel deck with a variable cross section together with the use of external prestressing tendons in the central span allows a substantial reduction of structural weights. The resulting footbridge requires a proper model for the assessment of its behavior up to the ultimate limit state as well as attention to vibration control under pedestrian loading at the service limit state. The former issue is addressed through the use of a specifically developed material and geometric nonlinear finite-element formulation. Regarding vibration control, an original combination of two different systems is used, i.e., high damping rubber (HDR) stripes and tuned mass dampers (TMDs). The HDR stripes, applied between the steel deck and the concrete floor, increase the overall damping of the footbridge, whereas t...

Abstract: Because a large longitudinal force exists in hybrid girder cable-stayed bridges due to the cable tension, its transfer mechanisms on the steel-concrete combination segment would be an important issue. In this study, experiments and theoretical analysis were conducted to characterize the longitudinal force transfer mechanisms of the steel-concrete combination segment in hybrid girder cable-stayed bridges. Five full-scale local structure specimens were designed and manufactured based on the original design of the steel-to-concrete transition zone according to a completed cable-stayed bridge in China. The specimens were subjected to monotonic loading and tested up to complete failure. The load-slip curves; stress distribution and failure modes, which varied with the thickness of the bearing plate; and the shear connector distribution were obtained. To simulate the test properly, calculation methods for predicting the shear connector capacity and corresponding load-slip curves were proposed based on t...