Abstract:In this study, an innovative split precast assembly technique for bridge cap beams is proposed, and its structural performance is investigated via experimental testing and finite element analysis. A scaled (1:3.6) sample was tested to evaluate the flexural behavior, crack resistance, and ultimate capacity of the split precast cap beam. The results indicate that the proposed technique achieves moderately reinforced flexural failure at cantilever roots with satisfactory ductility, with average crack resistance and safety reserve coefficients of 1.15 and 1.74, respectively. Strain analysis confirmed effective composite action between the precast components and the postcast strip, validating the space plane-section assumption. The experiment reveals localized stress concentrations at the beam ends and cantilever roots that require special reinforcement detailing. A nonlinear finite element model was developed and validated against test data, which showed good agreement and successfully captured behavior, including crack initiation and failure modes. The split precast technique has been successfully implemented in approximately 40 cap beams for the Outer Ring East Section traffic improvement project in Shanghai, China. The findings provide both theoretical and practical foundations for optimizing and promoting this efficient construction method in bridge engineering applications.

Abstract:This paper focuses on the challenge of insufficient transverse seismic capacity in urban elevated twin-column pier bridges. By conducting finite element simulations, it studies how externally reinforcing pier columns with Fiber-Reinforced Polymer (FRP), Engineered Cementitious Composite (ECC), and Ultra-High Performance Concrete (UHPC) affects their bearing capacity, stiffness, ductility, and energy dissipation. The results indicate that UHPC significantly enhances the bearing capacity of concrete columns, while both ECC and UHPC effectively improve ductility and energy dissipation. In contrast, FRP reinforcement shows no significant effect on bearing capacity, stiffness, or ultimate deformation. These findings provide reference data for strengthening similar projects.

Abstract:Using a practical engineering project as an example, this study analyzes a self-anchored suspension bridge under two different restraining systems: a fully floating system and a semi-floating system. This investigation focuses on static performance, overall stability, wind resistance, and seismic behavior. The static characteristics and dynamic responses of the self-anchored suspension bridge under different restraining systems are obtained, and the influence of the tower–girder constraint conditions on the mechanical behavior of the structure is discussed.

Abstract:The focus of this study is the transition pier of the main approach bridge in a newly constructed project in Chengdu. It begins by introducing the configuration strategy for the prestressed tendon layout. A comparative analysis of sectional stresses is then conducted under prestress loading conditions and at the completed bridge stage, using both spatial frame models and spatial solid models. Special emphasis is placed on investigating the torsional shear stress induced by structural and loading asymmetry in the L-shaped cap beam. The results show that the spatial frame models could meet practical engineering requirements. These findings provide valuable references for the design analysis of similar engineering projects.

Abstract:The J.P. Magufuli extradosed bridge is currently under construction. This bridge crossing Lake Victoria has an overall length of 3,000 m and a deck width of 28.45 m to accommodate 4 lanes of 3.5 m wide carriageways of vehicular traffic, a shoulder of 2.5 m+2.5 m for emergency parking and vehicle breakdown on each side, a 2.5 m+2.5 m footpath for pedestrians on each side, and a median of 2.45 m. The structural arrangement of the main bridge is 100 m+160 m + 160 m+100 m = 520 m, and the approach bridge prestressed concrete (PSC) beam bridge L = 2,480 m (including 31@40=1,240 m on each side). The superstructure is an extradosed bridge with an RCC deck with three RCC pylons 18.856 m in height. The girder heights at the mid-span and end-span are 5.4 m and 3.2 m, respectively. This paper discusses the construction aspects of the J.P. Magufuli bridge along with the details of a special traveling formwork (Form-Traveller) that is used to enable balanced cantilever construction, Pylons, PC House construction for the Pile Cap, and Deck Slab Partial Depth Panel for Deck Slab Construction.

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