Abstract:To analyze the applicability of the direct design method to the box-filler hollow floor, 224 specimens of cast-in-situ box-filler hollow floor and solid floor supported by columns were computed by ABAQUS. Both a hollow core floor and the corresponding solid floor were analyzed and the section moments were achieved. Then parametric analysis of the hollow floor was carried out. The column size ratio, hollow ratio, span ratio, beam relative flexural stiffness and beam relative torsional stiffness were all considered as analysis parameters. The first-round and second-round moment distribution coefficients in both interior and edge panel were obtained. The results show that: for the hollow floor and solid floor, the moment distribution in interior computational strip and edge computational strip are similar, the difference of moment distribution mainly lies in the positive moment. When the span ratio≤1.0 and the column size ratio≤0.2, the impact caused by support size can be ignored; There is still a relatively large gap between calculated value in moment distribution coefficient and codes in some part of the critical sections, some coefficient must be adjusted. From the analysis results, the first-round and second-round moment distribution coefficient tables were presented for research and engineering design.