Abstract:Prefabricated assembly construction has become a trend in urban bridge construction. However, urban wide bridges with high traffic demand usually have a large number 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 caps has been widely valued and developed rapidly. In this paper, the prefabricated assembly technology for bent caps is classified, and typical engineering cases are introduced. The performance research status of prefabricated bent caps is summarized, as are the existing shortcomings and improvement directions of prefabricated bent cap assembly technology

Abstract:The structural characteristics of four basic types of bridges, beam bridges, arch bridges, cable-stayed bridges, and suspension bridges, were summarized in this paper. A bridge type quadrant diagram was constructed using the orthogonality of beams and piers (towers) and the symmetry of bridge structures. Based on the bridge type quadrant diagram,① It was proven that there are only five basic bridge types. ② The structure and mechanical characteristics of the fifth type of bridge, called the umbrella truss bridge, were summa-rized.③ The structural features of the umbrella truss bridge were analyzed and optimized, leading to the identification of a corresponding real bridge after optimization. The real bridge not only verified the authenticity of the fifth basic bridge structure derived from the bridge type quadrant diagram but also validated the bridge type quadrant diagram proposed in this study. The results of this study provide a valuable attempt and discussion for perfecting and guiding the research and development of theoretical bridges.

Abstract:In recent years, the use and promotion of prefabricated assembly construction in China have been rapidly advancing, especially when combined with prestressing technology and Ultra-High-Performance Concrete (UHPC) as a new material to solve the connection and node construction between assembly components. It has started to be widely applied in developed coastal areas of China. This paper focuses on the node connection part of the prefabricated assembly construction used in the Shanghai Riverside Channel project. It explores the application of UHPC material in the assembly process and verifies the reliability of the relevant connection nodes through various experiments. The successful application of this research has been implemented in the Shanghai Riverside Tunnel project.

Abstract:To address the poor corrosion and fatigue resistance of the suspenders in tied arch bridges, a method using carbon fiber-reinforced polymer (CFRP) suspenders on tied arch bridges is proposed. The mechanical properties of tied arch structures and suspenders under different replacement principles are studied, and the equal area principle is selected as the material replacement method. The static responses of structures supported by CFRP suspenders and steel strand suspenders under different loads are compared and ana-lyzed using finite element software. The differences in stress variation between the two approaches are relatively slight, and CFRP can effectively replace steel strands as the material for tied arch bridges. The load-bearing capacities of the suspenders are compared and analyzed based on the “short hanger effect”. Compared with full-bridge suspender replacement, single-suspender replacement is more effective and feasible for real bridge applications. An actual engineering case using CFRP suspenders on tied arch bridges is analyzed, which provides new insights for the development of tied arch bridges.

Abstract:Although partial ground-anchored suspension bridges provide economical and feasible technical solutions when constructing ground suspension bridges under soft-soil geological conditions, the main girder bears a relatively large stress under anchor force. In this paper, analyzing the specific steel box composite beam with the Ultra-High-Performance Concrete (UHPC) bridge deck, we investigate the adaptive capacity of the main beam of the partially ground-anchored suspension bridge. Through the analysis of ground anchor forces, the maximum ground anchor force within the allowable stress range of the pavement layer is de-termined. This provides a basis for determining the corresponding cable forces, anchor forces, and anchor dimensions, offering valuable insights for the design of partially ground-anchored suspension bridges.

Abstract:Cable-stayed bridges, due to their unique mechanical structure, have the ability to span larger distances, therefore, they are increasingly emphasized in modern bridge construction. With the continuous im-provement of engineering requirements, cable-stayed bridges have gradually become a primary bridge type for long-span structures. Due to the complexity of cable-stayed bridge structures, to ensure that the actual construction state of the bridge is close to optimal, the bridge must be strictly monitored and con-trolled during construction. In this paper, Jinwu Bridge in Jinhua, Zhejiang Province, is taken as the research background. This bridge is an asymmetric single-tower cable-stayed bridge. The spans and materials of the main girders on both sides of the bridge pylons are different. During the tensioning of stay cables, the space effect of the main girder is prone to generating an unbalanced moment. Herein, a study on the tensioning scheme of stay cables is carried out. The results show that, compared with those of the one-time tensioning scheme for stay cables, the stress state and cable force of the bridge are better when the two-time tensioning scheme is used, meeting the construction monitoring requirements.

Abstract:The Yuanyang-Zhengzhou section project (the Lanyuan Expressway to Lianhuo Expressway) of the An-yang-Luoshan Expressway project is an important part of the Jingwu Expressway in the national ex-pressway network. The project straddles the Yellow River Wetland Reserve and plays an important role in the construction of the Yellow River economic axis. It is of great significance to promote the integrated development of cultural tourism, to promote the core demonstration of ecological protection in the Yellow River Basin and to help the high-quality development of the Yellow River.