The Application And Research Of The Light-weight Steel Truss Net Support Used In The Construction Of The Arch Bridges

Light-weight steel truss net support is a new type of support used in the construction of the arch bridge with small or medium span. With the advantage of light weight, simple manufacturing process and so on, it is appropriate for the construction of arch bridge which a high demand of foundation. Its popularization and application can shorten the construction time, reduce the construction cost and brought great social and economic benefits. For the lack of relevant theoretical and practical experience as a guide, it is very necessary to make an intensive study of the new type support.In this paper, a combination of practice and theory research is done to the Light-weight steel truss net support used in the arch construction of the Changtianyang Bridge in Huzhou, Zhejiang Province, China. The main work and achievements of this paper are as follows:(1)The study of the theoretical analysis of the structure shows that the steel truss net support can meet the standard of construction requirements. The structural calculation includes three aspects:strength calculation, stiffness calculation and stability calculation. The strength calculation of the steel truss net support is reduced to the strength calculation of a single piece steel arch because of the steel tube turning uniform load into concentrated load.(2)The monitoring data including the displacement data and the stress data of the steel truss net support is extracted in the monitoring process. At the same time, a finite element model is built using the large finite element analysis software Midas Civil to get the finite element analysis results of the structural displacement and the stress of structural member. The comparison of the monitoring results and the finite element calculation results shows that the finite element model calculation results can reflect the mechanical performance of the steel truss net support used in the arch bridge construction.(3) The static analysis and buckling analysis is made on the structure by use of the finite element model, the results of which give a theoretical support of application.(4)Due to accidental events during the construction, failure pole appears on the structure which may lead to total progressive collapse. In order to prevent collapse of the structure, it is necessary to analyze the structural progressive collapse. In this paper,12 types initial damage are chosen to analyze the structural collapse of the steel truss net support used in the Changtianyang Bridge. The analysis shows that the structural progressive collapse would not happen under the 12 situation. But further study on the steel truss net support’s collapse analysis is needed to ensure the safety of construction of the bridges.In the end, all the analysis result show that the light-weight steel truss net support can be used in the construction of the small or medium arch bridges intensively. While the design of the structure should be optimize when the steel truss net support will be used in a arch bridge with different structural parameters.