The Theoretic Study On Thin-wall Core Box Cast-in-site Prestressed Concrete Hollow Floor System

The great span cast-in-site hollow ceiling structure system, act as the science and technology popularization application project of Construction Ministry in 2004, which is obtained the promoted application throughout the country.With the unceasingly springing up of new pre-stressed material and new craft and the progressive perfection of pre-stressed structural theory,this technology also be applied more and more widely. If the pre-stressed technology and the new section form of ceiling structure can be unified,develops the new pre-stressed ceiling structure with lighter dead weight and bigger rigidity,so as to fully exert the superiority of two technology, greatly promotes respective application scope,applies to the big column net great standard width,it will be able to obtain good economy and social efficiency.The pre-stressed thin wall box body spatial web plate ceiling was analyzed in this article based on the reasons,the research results has been obtained states as follows:1.The schematic analysis of the ceiling construction structure has been conducted,based on the reference circular pipe pre-stressed hollow ceiling,has formulated the corresponding construction flow, and has carried on the discussion flat beam pitch point of the large-span ceiling.2. Has analyzed the pre-stressed steel and concrete interaction,established the finite element analysis model of cast-in-site pre-stressed thin wall box body earth hollow ceiling,used ANSYS finite element software to analyze to it,and has carried on the contrast with the solid ceiling in stress and strain.3. In the consideration pre-stressed steel situation,make a deduction about the computation of hollow ceiling by stimulating sandwich plate method and deflection computation through an example,it has no obvious difference from the finite element analysis result,thus confirmed this feasibility of method.4. Used the design method that estimates the pre-stressed steel firstly and calculate the ceiling by commonly used calculates software,it has a good agreement with the finite element computed result by comparison,thus proved the general structure computation software can be able to use in the ceiling design.5. The equivalent load analysis of equal-span pre-stressed steel statically indeterminate structure introduced briefly in the article,has made internal force comparison between the solid ceiling by the finite element method,it has no obvious difference in internal force distribution and distortion from the solid core, thus we can use equivalent frame law to do the ceiling computation.