Research On Design And Key Construction Technology Of 125m Four-span Continuous Movable Shuttering System

The movable shuttering system is a kind of self-supporting formwork,which can use bearing platforms or piers as supports and can move between the bridge positions and build the large-scale bridge construction equipment for cast-in-place construction of box girders.Compared with the traditional construction methods,the movable shuttering system has many obvious advantages such as high construction speed,high mechanization degree,wide application scope,economical reasonableness,and good bridge structural integrity.However,in China,bridges constructed using the movable shuttering system have a large majority of bridges with a standard span of 30 to 50 m in China,and are usually single-span cast-in-place movable formworks.But domestic related research and application are still less for the design and apply of ultra-long and multi-span continuous movable shuttering system.This paper based on the design and application of movable shuttering system at home and abroad and relevant literature research,and takes the Yancheng Expressway Network Q1 marked Xihuan Bridge Viaduct as the engineering background,a new 125 m four-span continuous movable shuttering system method was proposed.This paper has carried out a series of research work on the structural design of the new movable shuttering system,finite element analysis of the structure,key construction technology,construction monitoring technology,etc.The main research contents and results are as follows:(1)This paper proposed a design scheme for a new type of 125 m four-span continuous movable shuttering system.The structural design of the various parts of the movable shuttering system was described,the structural shapes,dimensions,materials,and main functions of the main beam,bovine leg beam,bovine leg support,guide beam,sliding trolley,formwork system,and formwork beam were designed and determined.And the main technical parameters of the movable shuttering system were established in this paper.(2)In this paper,the finite element analysis of the main components of the movable shuttering system under the pouring and through-hole working conditions was performed by using MIDAS software.The results show that the movable shuttering system meets the strength,stiffness,and stability requirements of existing related specifications under pouring and through-hole working conditions.(3)In this paper,a complete set of key construction technology,such as assembly,preloading,lifting,concrete pouring,through-holes,and demolition of movable shuttering system,was analyzed and studied,and a set of engineering and technical solutions for the construction of concrete box beams with a strong long and multi-span continuous movable shuttering system was formed.(4)This paper studied and designed the stress monitoring and deformation monitoring scheme of movable shuttering system and analyzed the monitoring results.The monitoring results show that the maximum stress value and deformation value of each measuring point do not exceed the relevant specification requirements.The monitoring value is generally less than the finite element calculation value,but it is consistent with the trend of the calculated value,the law of change is reasonable,and the repeatability of the test result is good,indicating that the movable shuttering system is in a safe state during the construction process,which means that the design of the movable shuttering system is successful and feasible.Through the above research and analysis work,the conclusion and results of the research were systematically summarized,and some other key issues and further research directions in the future were put forward in this paper.The research work of the paper provides a good reference for the application and promotion of the design and construction technology of the long and multi-span continuous movable shuttering system.