| With the continuous development of urban construction in China,a large number of bridges have been built on the highway.Among them,prestressed concrete bridges are generally used in bridge construction because of their low cost and structural stability.From a comprehensive view of the development trend of bridge construction,it can be seen that the current bridge construction is developing towards a larger and longer trend direction,and it also pays more attention to bridge aesthetics and environmental protection.Therefore,the super-long prestressed construction technology of cast-in-place girder bridges will be more and more widely used in bridge construction in China.However,it is also necessary to solve the technical problems such as the difficulty of penetrating the steel strands in the long construction of the prestressing tendons,the stenciling process is not strict,and the vacuum pressure grouting is difficult to be compacted after the tension is completed.This topic takes the Dongli Zhiguang Bridge with 155 m variable cross-section continuous box girder structure as the carrier of the reconstruction project of Jinzhong Highway(the extension line of the west section of Dongli Zhiguang Avenue).The structural integrity is high,and it is required to achieve an aesthetic effect.Therefore,the main web of the box girder is constructed with super long prestressing tendons.Through the study of the technical problems,such as extra long steel strands,tension process control and guaranteeing grouting density,the main content of quality problem control in the construction of super-long prestressed tendons,in the construction of super-long prestressing tendons of cast-in-place box girder bridges,the construction schemes and technical measures are formulated to optimize the construction technology.The quality problems appearing in the construction process are solved and the engineering quality is guaranteed.Through research,we can improve the construction process,shorten the construction period,reduce the construction cost,ensure the quality of the project,and improve the overall economic benefits of the project.The construction method studied in this paper has certain technical guiding significance for the same field in the same industry and promotes the maturity of the construction technology.At the same time,it brings considerable economic and social benefits.The research results of this project will be applied to all domestic bridge construction enterprises. |
