Analysis On The Force Infection Of Steel Reinforced Concrete Transition Truss

Because of its high capacity, conducive to the construction, excellent seismic performance, steel reinforced concrete (SRC) transition truss is widely used in various projects. Due to the large span, transition truss will have a greater load effect under the vertical loads for such buildings. The force of truss will have greater impact on different boundary conditions between truss and other components. In this paper, taking the Guizhou provincial office building as the engineering background, established finite element analysis model of the structure with SRC transition truss by finite element analysis software ANSYS. Contrastive analyzed the finite element model for the factors like connection, composition, construction impact, etc, clear the influence of factors on the truss. Combined with monitoring data during construction phase, analyzed the cause of the truss stress state, determine the force situation under service stage. Main contents and conclusions are as follow:(1) Established finite element analysis model of the background project by ANSYS, analyzed the factors affecting internal force of the SRC transition truss. Conducted major study in extension of steel, lateral connection beam, the lower support, floor layout, arching and tension bar weaken. The results show that SRC transition truss stress of their situation is different from the ordinary truss force, but related to a greater relationship with arrangement of structural elements and connections.(2) Analyzed the monitoring data of the truss during construction phase. Combined with the impact of factors, preliminary determined the causes of the truss force during construction phase. Identified the role of main infection factors played in the truss force: arching, the lower support and tension bar weaken are the major reasons for arch bear more and suspender bear less; The main reason for truss components'compression during construction phase is settlement difference which comes from different load distribution between design and construction, it cause the tubes incline to the middle, extruding truss while it transfer upper load.(3) Compared with the original model, model result considering infection factors is more close to the monitoring data in form and trend, confirm the monitoring data, explain the causes of the state of truss, better reflect the real situation of each component, laid the foundation to accurately judge the situation of the project in service stage. (4) Carried out static analysis, modal analysis and seismic response spectrum analysis in modified model. Analysis shows that truss and structure is in the normal force state, meet the design requirements, have not been significantly affected by the unusual form in the construction phase.