Abstract:As a new type of spatial structure, the large-span asymmetrical saddle-shaped cable network structure has the characteristics of novel shape, large span and less steel, and is mainly used for large public buildings or sports venues. In this paper, based on the roof of Panjin Stadium, a large number of simulation calculations and scheme comparison are carried out in view of the structural characteristics of the large-span asymmetrical saddle-shaped cable network structure, and the construction method of "ground assembly, synchronous lifting and integral tensioning" is proposed. The tensioning test was carried out on the 1∶10 structure model to verify the correctness of the simulation calculation and the feasibility of the construction method. Five key technologies of the construction method, such as the whole process simulation calculation analysis, cable cutting, synchronous lifting technology, integral tensioning technology and construction monitoring technology, are studied deeply. The research results have been successfully applied in the construction of Panjin Stadium roof, Foshan Furniture City roof and Xuzhou stadium roof space cable structure, and have achieved good results, which can provide useful reference for the tensioning of such structures

Abstract:The Tuanhe Aqueduct project of the first phase of the Middle Route of the South-to-North Water Transfer Project has a novel structure, complex force, and the structure size ranks first among similar projects in China. It is an independent 3-channel fully prestressed concrete U-shaped thin-wall structure with a single span length of 40m and a single span weight of about 1600 t. Through the research on the prestressed construction technology of super-large cast-in-place U-shaped aqueduct, the mechanized construction of Tuanhe aqueduct body is realized, the project period is greatly shortened, and the construction cost and investment are saved.

Abstract:Based on the stress failure of a hollow slab bridge, a design scheme of replacing the hollow slab with a post-tensioned prestressed T-beam with variable height is proposed. The beam end of the structure scheme is equal to the height of the original hollow plate beam, and the height of the middle span beam is increased appropriately, so that the bridge span structure can be renewed without changing the elevation of the original bridge floor. For this reason, the rib spacing of T beam is sealed in the section structure (smaller than that of general transverse assembly T beam), the prestress reinforcement is optimized, and two shear reinforcement structures "embedded steel plate" and "shear reinforcement skeleton" are designed at the end of T beam, which can provide reference for the renovation design of similar projects.

Abstract:Based on the engineering background of a long-span suspension bridge with a main span of 500 m, the buffeting response of a long-span flexible suspension bridge under fluctuating wind loads is analyzed and calculated, and some useful conclusions are obtained. Modal analysis shows that the natural vibration frequency of long-span suspension bridge is low, which is a typical wind-sensitive flexible structure. When the buffeting force and self-excited force are considered at the same time, the maximum buffeting displacement response of the main beam of the suspension bridge can be obtained according to the extreme value theory. The results show that the maximum buffeting displacement response in the vertical, horizontal and torsional directions all occur in the middle of the main span, and the value is large, which cannot be ignored in the structural design.

Abstract:Cable hoisting crane is the key equipment for erection of stiffening beam of large suspension bridge. From its working condition, it belongs to the category of special hoisting equipment, and its safety has attracted much attention. As a new type of bridge erection equipment, there is no official national standard. Through the design of structure, machinery, hydraulics and control of cable-borne crane, the safety of cable-borne crane is verified through the inspection test in the factory and in the field, and the key construction technology of cable-borne crane is proposed.

Abstract:As a type of prestressed system, the anchorage system of rolled threaded bar is an important factor in the application of prestressed concrete engineering. In this paper, the anchorage system of prestressed rolled thread reinforcement has the characteristics of large diameter, high strength, low relaxation and small shrinkage. The successful application of φ75 and φ85 roller threaded steel bars and their anchoring systems in Hong Kong-Zhuhai-Macao Bridge and Nanning Yinghua Bridge shows that the excellent performance of the roller threaded copper bar anchoring system has played a good role in promoting the application of bridge prefabrication segment-assembly technology to form pipelining lines and accelerate the construction progress.