Structural Design And Floor Vertical Vibration Analysis Of Long-span Concrete-filled Steel Tube Arch-frame Structure

In the design process of a skybridge with a net span up to 76 meters in a large public construction project,the technology of arch structure in bridges is applied,which is named as “a long-span concrete-filled steel tubular arch structure supported by barrels at two ends”.With research on this innovative structural form,a calculation method involving its strength,rigidity,the whole stability and anti-seismic performan-ce,as well as a principle for structural arrangement,construction and reinforcement measures,are recommended.Through vertical vibration serviceability analysis of the slab floors for this long-span spatial arch structure,theoretical references are provided for similar cases in structural design in the future.The main content of this dissertati-on is listed as follows:1.Analysis of the anti-seismic performance of the long-span concrete-filled steel tubular arch structure.2.Given the specificity of this arch structure,several groups of comparative models are set as follows: basement or non-basement;slab floors or non-slab-floors;brace or non-brace in slab planes;arch supported by either fixed or slipping barrel bearings;tie bar or non-tie-bar between arch ribs,and so on.Examining the mechanical property,stability and anti-seismic performance of the groups of models listed above,recommendation for design is provided.3.Solid finite element analysis for a crucial joint-a connection joint among arch rib,tension bars and supporting barrel-is adopted in order to analyze its stress and strain properties in several main load cases,therefore effective measures for improvement in construction practices are recommended.4.Considering the characteristics of a long-span concrete-filled steel tubular arch structure,specific calculation methods for vertical vibration serviceability of this form of slab floors are recommended,particularly focusing on the distribution pattern of pedestrian,values of excitation loads,selection of crucial sections and serviceability evaluation in slab floors analysis of similar multi-storey spatial structure.5.A simulation analysis of the construction process is adopted to determine a reasonable construction sequence,which can influence the mechanical property of the arch structure,in order to optimize the design process,and to make full use of material strength,lest the most adverse condition occurs during the construction.Moreover,theoretical data-stress and strain-are compared with those obtained by field monitoring to prove the validity of this method.