Study On Analogue Slab Method Considering Shear Deformation For Box-shaped Hollow Floor

The box-shaped hollow floor is a type of hollow floor, whose cavities are formedby shin-wall boxes which are placed between concrete slabs. It has broad prospects inapplication because of the advantages such as high hollow ratio, light weight, saving inmaterials, reasonable form of mechanics, convenient construction, etc. Methods whichare more suitable for structure analysis of the box-shaped hollow floor are the analogueslab method and the analogue cross beam method. The current studies have not yetproposed systematic comparisons and evaluations for the accuracy of differentequivalent ideas, and not considered the effect of shear deformation. This paper studiesthe issues related to the structural analysis of box-shaped hollow floor using theanalogue slab method, deflections and internal forces on the basis of different simulatedmethods were compared and analyzed, and the existing code was supplemented byconsider the effect of shear deformation. The main work and conclusions are as follows:1Using three representative equivalent methods of the analogue slab method, inthree boundary conditions, the box-shaped hollow floors with different kinds of hollowratios were equivalent to flat plates, the deflection and bending moment were calculatedthrough the elastic plate theory, and were compared with solutions of ABAQUS finiteelement hollow floor solid models. From the results, the simulated method in "in-situconcrete hollow floor technical regulations JGJ/T268-2012" is more consistent with theoriginal structure than the other two methods. Also found that there are a few of errorsbetween the deflections calculated through this method and the actual value of hollowfloor.2The box-section beams with different kinds of hollow ratios and span-depthratios were equivalent to solid rectangular cross-section beams base on the analogueslab method in existing code, the deflection comparison results between them show thatthis method only considers the equivalence of anti-bending stiffness, so that theequivalent solid plate did not accurately reflect the shear deformation of original hollowfloor, and in some cases make the deflection were calculated with large errors.3On the basis of analogue slab method in existing code, considering the shearstiffness of hollow floor is equal to the shear stiffness of solid plate, a "equivalent shearmodulus" for solid plate was get. And the shear modulus was proved that it canaccurately calculate the shear deformation by numerical examples. This method achieve a complement to the analogue slab method in existing code from two aspects: theoryand ABAQUS program, so calculating the deflection by the improved method makedeflections of plates and the value of original hollow floor closer.4Using analogue slab method considering shear deformation, proposed theestablishment of a solid plate model in ABAQUS program, instead of establishing ahollow floor model to calculate deflection. This method simplifies the modeling processand improve the efficiency of the analysis and mesh quality, and the analogue slabmethod can be used for the hollow floors under more complex boundary conditions.