Analysis On The Flexural Performance Of Low Height Multi-ribbed Type Pre-stressed Concrete Simply Supported T Beams

Among all the existing bridges,hollow plate structure,as a commonly used superstructure for small and medium-span bridges,accounts for a large proportion.To solve its hinge joints problem and other fatal problems,an idea of changing single support into dual support,getting rid of hinge joints,and replacing open section with closed section occurred.As a result,low height multi-ribbed type pre-stressed concrete simply supported T beams have been introduced.As a relatively new structure for small-span bridges,there hasn’t been a full-scale failure test or fatigue analysis,so in this paper,the overall flexual performance of low height multi-ribbed type pre-stressed concrete simply supported T beam bridges and how beams react to loading are mainly studied,based on the practical engineering project,the Fanjiagang Bridge on the expressway from Bei’an to Fuyu,in order to facilitate further optimization of the design,to provide the theoretical basis for the structural damage of this type of beam bridge and to ensure the bridge safety.Meanwhile,the results of this study can also be used for the design of small-span bridges.In this paper,the typical load-deflection curve,the strain distribution of the tensile steel bar,the strain distribution along the beam height of the concrete and the failure form of low height multi-ribbed type pre-stressed concrete simply supported T beam have been obtained from the full-scale failure test.Midas FEA was used to build the three dimensional finite element model for the tested beam.The rotating crack model under total strain crack model was applied to the non-linear model;Thorenfeldt curve was used to simulate the full curve of compressive stress and strain of concrete;Constant curve was used to simulate the tensile stress-strain full curve of concrete.The results of the finite element simulations for the static elastic phase and the failure stage of are in good agreement with the test results,which makes the whole failure process of the test beam and how it reacts to the loads more clear and intuitive.From the results of the static analysis and the experiment,we can tell that low height multi-ribbed type pre-stressed concrete simply supported T beam is a new type of bridge structure with good performance and durability,but lacking a bit of rigidness.With some improvements,it can be widely used in small-span highway bridges to replace hollow slab beams.The studies in this paper can provide the experimental data and theoretical basis for the establishment of the related calculation theory for the same type girder bridges,which has a certain referential significance for its further improving on the design.