Volume 3,2025 Issue 01

>Scientific Research

• Performance of Column with Upper-Anchored Grouted Corrugated Duct Connections Under Load

  Jie Zhang, Chenxi Fu, Yuanhong Fu, Siyuan Li

  2025,3(01):1-13 ,DOI: 10.59238/j.pt.2025.01.001

  Abstract(56) HTML(17) PDF(1.63 M)( 107)

  Abstract:The core goal of the prefabricated construction of urban prestressed concrete bridges is to improve structural performance and construction efficiency. To improve the construction convenience and load-bearing performance of the connection between precast columns and pile caps, a novel connection structure for upper-anchored grouted corrugated ducts is proposed in this study. By comparing the pushover damage process of the integral casting column, the column connected by the grouting sleeve and the column connected by the upper-anchored grouted corrugated duct, the effects of the column height and the axial compression ratio on the performance of the column connected by the grouted corrugated duct were analyzed. Research results indicate that columns with upper-anchored grouted corrugated ducts exhibit superior static performance and ductility, with horizontal load-carrying capacities 23% greater than those of integrally cast columns and ductility performances 98% greater than those of integrally cast columns. Additionally, the primary concrete damage areas of these structures are farther from the bottom joint interface, featuring a wider distribution range of damaged areas and higher plastic hinge heights. When designing connections for columns with upper-anchored grouted corrugated ducts, controlling the elastic curvature ratio at section locations (sections with enlarged dimensions and sections at the base of columns) to be no less than 1.8 is recommended.

>Reviews

• Research Status of Structural Optimization Design, Materials, and Prestressing Techniques for PC Small Box Beams: A Review of Research Progress

  Fangyuan Li, Luda Li

  2025,3(01):14-34 ,DOI: 10.59238/j.pt.2025.01.002

  Abstract(68) HTML(30) PDF(1.00 M)( 100)

  Abstract:Based on recent research findings and an analysis of the literature on Precast concrete (PC) small box girders, this paper presents a systematic discussion of the optimization design, materials, and prestressing techniques for PC small box girder structures. The study analyzes and summarizes the optimization design of PC small box girders in terms of diaphragms, prestressing tendons, cross-sectional dimensions, and materials. It synthesizes the impact of these optimization methods on the mechanical performance of PC small box girders. Furthermore, the current research status of retard-bonded and external prestressing technologies is discussed in detail, along with a summary of the mechanical properties of small box girders utilizing these techniques. Finally, several future research directions are proposed on the basis of the current state of research.

>Product Research and Development

• New Durability Assurance Technologies for the Shenzhen–Zhongshan Cross-Sea Bridge

  Huanyong Chen, Di Wang

  2025,3(01):35-47 ,DOI: 10.59238/j.pt.2025.01.003

  Abstract(63) HTML(13) PDF(2.46 M)( 99)

  Abstract:The Shenzhen–Zhongshan Link (Shenzhong Link) is the world's first integrated cross-sea cluster project featuring a "bridge-island?tunnel-undersea interchange", and it is a key national project. The main structures include a 17-kilometer-long sea-crossing bridge and a 6.8-kilometer-long submarine tunnel. The project officially opened to traffic on June 30, 2024, with an average daily traffic volume of approximately 90,000 vehicles. Owing to the alternating loads from vehicles as well as wind, waves, and currents, fatigue issues are prominent. Moreover, the structures are exposed long-term to a marine environment characterized by high temperature, high humidity, and high salinity (fog), leading to severe corrosion problems. Considering that both corrosion and fatigue, as well as their coupled effects, significantly impact structural durability, this paper conducts research on key technologies for ensuring the durability of the Shenzhen–Zhongshan Cross-Sea Bridge, with a particular focus on marine concrete, steel beams, and main cables.

• Study on the Design and Optimization of the Mix Proportion for High-Grade Concrete for the Pylon of a Long-Span Suspension Bridge

  Xiaoliang Zhu, Baoan Quan, Sheng Fang, Hao Wei, Junchen Zhao

  2025,3(01):48-63 ,DOI: 10.59238/j.pt.2025.01.004

  Abstract(47) HTML(12) PDF(1.79 M)( 92)

  Abstract:In this paper, an in-depth study was conducted on the design and optimization of the mix proportion of C55 high-fluidity pumped mass concrete for the northern pylon of the Longtan Yangtze River Bridge. During the mix proportion trial and initial adjustment phase, the W/B ratio was determined in accordance with relevant standards, and the performance indicators of the aggregates were comprehensively considered to select coarse and fine aggregates based on scientific evidence. The range of mineral admixture proportions was determined on the basis of performance and cost considerations. Through a series of experimental studies, the influence of various factors on the workability of concrete was determined, and the initial mix proportion was preliminarily established. Further exploration of the effects of cement type and functional aggregates revealed that the workability of the project cement was inferior to that of Onoda cement, but the concrete was not replaced for cost reasons. Functional aggregates can enhance concrete performance from various aspects, but may slightly reduce compressive strength. The multiobjective mix proportion was further optimized and subjected to performance verification. After functional aggregates were added to the optimized mixture, the concrete exhibited excellent workability and met the strength requirements. Thermal insulation aggregates effectively mitigated an increase in concrete temperature, whereas heat-storage aggregates provided good initial temperature control during pouring. Through more than 20 sets of experiments, multistep optimization, and verification, the key factors and their mechanisms in mix proportion design were clarified. This study provides a systematic methodology and practical basis for the design of high-strength, high-fluidity mass concrete, ensuring the safety and durability of projects.

>Project Report

• Landscape Design of the Fujiang River Bridge on Sci-Tech City Avenue in Mianyang, Sichuan

  Xin Tian

  2025,3(01):64-72 ,DOI: 10.59238/j.pt.2025.01.005

  Abstract(38) HTML(14) PDF(1.62 M)( 83)

  Abstract:The Fujiang River Bridge on Mianyang Sci-Tech City Avenue, located in Sichuan Province, is a critical node project of Sci-Tech City Avenue. Its main bridge, spanning the Fujiang River, is a single-span 255-meter under-slung basket-type steel box tied-arch bridge. Based on the design principle of "structure as landscape", the design adopts the theme “playing strings and composing rhymes”. It extracts “lines” as landscape design elements, integrating bridge functionality, visual aesthetics, and force characteristics. The arch ribs are designed with a 1.9-order parabolic shape, while the stay cables are arranged radially. The deck uses steel box girders to achieve tie rod functions, forming an image of “strings-bow body-harp base”. The bridge plaque is themed “Riding the Waves of the Fujiang River”, featuring a curved design. Night scene design employs dynamic lighting to enhance the imagery of harp strings through the interplay of light and shadow on the arch ribs and stay cables. Through integrated structural-landscape design, the project has become a technological culture landmark in Mianyang, enhancing traffic efficiency and urban imagery.

>Research Report

• Research Planning and Experimental Study on Soft Soil Foundation Suspension Bridges

  Yan Xu

  2025,3(01):73-82 ,DOI: 10.59238/j.pt.2025.01.006

  Abstract(39) HTML(10) PDF(1.34 M)( 99)

  Abstract:Taking the Jiasong Highway Bridge over Huangpu River in Shanghai as the research background, multiple schemes were proposed for comparison, and detailed scientific research planning was carried out on the basis of the characteristics of soft soil foundations during the project promotion process. Focus on the planning of the scientific research project of the bridge and the implementation of key experiments.

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