Two-way Tube Hollow Plate Floor Well Grid Beam Structure Analogy Analysis

The cast-in-situ concrete hollow floor structure becomes a new construction form with the invention of new technology- pipeburying nondnockout core poreforming technic. One kind of the new forms is the hollow flat slab floor consisting of hidden-beam and hollow slab. As a new structure system, it has a great many advantages such as low structural height, small dead weight, high stiffness, prompt constructing, etc. It can be applicable to many buildings with various spans supporting multiple loads , especially to those buildings which have higher requirement on high-rise, deadweight , large space, and aseismatic capability. But few investigation are made on this kind of floor, hindering the application of this new technology. In this paper, the mechanical properties and calculating method of the floor are studied, for the sake of its widely application in practice in the future. The main contents are detailed as following:1. The numerical methods are put forth to decide the flexural stiffness in radial direction for a voided plate with paralleld circle-tubes with great efficiency, and the empirical expression is developed by correlation to calculate the ration of stiffnessλin radial to axial direction. It is found thatλin《Technical specification for cast-in-situ concrete hollow floor structure》is on the high side at large and too roughness. In addition, discussion on its shearing deformation effect is made, it shows that the effect in axial could be ignored and the radial is more evident than the axial.2. On the basis of three different analogue beam projects, the evaluation on the analogue beam method in specification is made, and it is found that this method do not define material operation project, and gets uncertain result inevitably in design, so it needs to be perfect.3. The single-grid voided plate is analysed with similitude girder, and then two improved analogue beam methods are put forward, which define girder's collocation and stiffness distribution. Comparison between their results and 3D finite element analysis results shows that the improved analogue beam method has maneuverability, and its results is stabile and credible.4. The experiment of the multilayer and multiple-panel unitary floor is finished. The model was approximately analyzed with the improved analogy methods of beam. Through comparing, the calculations and experiment results are close, and the approximate methods is more proved to be feasible.