Abstract:How to apply the spatial-grillage method reasonably to the beam-slab structure is discussed. Some deficiencies of the hambly-grillage method are put forward. Some influence factors of spatial-grillage method including the spatial arrangement and connection of the components after the structure is divided, the correction of section stiffness, diving rules and so on are analyzed. It is pointed out that the reasonable spatial-grillage model should include the increase of virtual nodes spatially and orthogonally arranged with web montant elements and member bars, and connect the torsional moment of inertia of the section based on the elastic mechanics principle, and try to ensure the same length of longitudinal and transverse bars. Finally, T-shaped beam and double girder structure are taken as the examples to carry out the test and solid analysis validation. The comparison results show that the result analyzed by the established spatial-grillage model is identical with the test and solid analysis data. And the analytical precision meets the engineering demands.