Abstract:The prefabricated assembly construction has become the trend of urban bridge construction. However, urban wide bridges with huge traffic demand usually have a large amount of lower structure bent caps. The length of the bent caps is often greater than 25 m, and the weight is usually more than 300 t. The transportation conditions of the overall prefabricated bent caps are limited by roads, and the overall lifting tonnage is too large. The precast assembly technology of bent cap has been widely valued and developed rapidly. In this paper, the prefabricated assembly technology of bent cap is classified and the typical engineering cases are introduced. The performance research status of prefabricated bent cap is summarized, and the existing shortcomings and improvement directions of bent cap prefabricated assembly technology are summarized.

Abstract:To address the issues of corrosion and poor fatigue resistance of suspension rods in arch bridges, a method of using CFRP (Carbon Fiber Reinforced Polymer) material for suspension rods in arch bridges has been proposed. By comparing the mechanical performance of the arch structure and suspension rod components under different substitution principles, the equal area principle has been determined as the method for material replacement. Finite element software has been used to analyze and compare the static response of the structure between CFRP suspension rods and steel strand wire under different load conditions, showing that the difference in stress variation between the two materials is small and CFRP can effectively replace steel strand wire as the material for suspension rods in arch bridges. Furthermore, the stress on the suspension rods has been analyzed based on the short suspension rod effect. Compared to the replacement of the entire bridge structure, the replacement of individual suspension rods is found to be more effective and feasible for practical bridge applications. The application of CFRP material in suspension rod arch bridges has been promoted through actual engineering cases, providing new ideas for the development of arch bridges with suspension rods.

Abstract:Partial ground anchor suspension Bridges provide an economical and feasible technical solution for the construction of ground suspension Bridges under soft soil conditions, but the main beam has a large stress range due to the action of ground anchor force. In this paper, through the analysis of UHPC bridge panel and ground anchor force, the changes of UHPC on the stress and deformation of the main beam are obtained. In particular, the allowable ground anchor force under the allowable stress range of pavement layer is determined through the analysis of ground anchor force, which provides a reference for the corresponding main cable force, anchor size and retention anchor force.

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Abstract:Due to the complex structure of cable-stayed bridges, strict monitoring and control must be carried out during the construction process in order to make the actual construction state of the bridge close to the ideal state. This article takes the Jinwu Bridge in Jinhua City, Zhejiang Province as the research background. The bridge is an asymmetric single tower cable-stayed bridge, and the main beams on both sides of the tower have different spans and materials. During the tensioning process of the cable-stayed cables, the spatial effect of the main beams is significant and unbalanced moments are easily generated. Conduct research on tensioning schemes for cable-stayed cables. The research results show that compared to the one-time tensioning scheme of cable-stayed cables, the stress state and cable tension of the bridge are better when using the secondary tensioning scheme, which meets the requirements of construction monitoring.

Abstract:The structural characteristics of four basic types of bridges were summarized: beam bridge, arch bridge, cable-stayed bridge and suspension bridge. The quadrant diagram of bridge type was constructed using orthogonality of beam and pier and symmetry of bridge structure. Basing on the bridge quadrant diagram,①It was proved that there were only five types of basic bridge types. ②The structure and mechanical characteristics of the fifth type of basic bridge structure called as the umbrella bridge were summarized.③The structural features of the umbrella bridge were analyzed and optimized, and the corresponding real bridge after optimization was finally found. The actual bridge not only verified the authenticity of the fifth basic bridge structure derived from the bridge type quadrant diagram, but also proved the correctness of the quadrant diagram of bridge type proposed in the present study. The results of this study provide a useful attempt and discussion for perfecting and guiding the research and development of theoretical bridge.