Study Of Load-bearing Properties Of The Concrete Fabricated Hollow-ribbed Floor

The concrete fabricated hollow-ribbed floor is a new floor system, composed of cast-in-site ribs and the prefabricated concrete box fillers. It is applicable to long-span building, and has been widely applied in some areas in China.In this thesis, an experimental investigation and finite element analysis on the ribbon of the fabricated hollow-ribbed floor was made. A section stiffness calculation method considering the effect of the prefabricated box fillers was proposed and promoted to the whole floor. The simplified calculation method of the concrete fabricated hollow-ribbed floor was fixed. This article is totally divided into five chapters, as follows:In the first chapter, the advantages and disadvantages of the domestic common large-span hollow floor types were summarized. And the innovative advantages, construction techniques, economic benefit and engineering applications of the concrete fabricated hollow-ribbed floor were introduced emphasisly.In the second chapter, through the static test research of the cast-in-situ model, the assembled monolithic model, and rib beam model of slab strips, the rigidity and bearing capacity of these three kinds of slab strips were analyzed and contrasted. In addition, the strain distribution of the box filler's top plate of the assembled monolithic model was analyzed, in order to study the prefabricated box fillers participating in global stress of the cast-in-situ rib beam, and confirm the existence of the shear lag phenomenon.In the third chapter, finite element analysis program ANSYS had been used to analyze the assembled monolithic and rib beam testing model, compare the rigidity and bearing capacity of the two models. And the result was compared with the testing. Through the method of extracting node stress, stress distribution of the box filler's top plate of the assembled monolithic model was got, and the existence of the shear lag phenomenon was confirmed.In the fourth chapter, according to test data and the finite element calculation result, the shear lag phenomenon was analyzed, the effective flange width was calculated, and compared with the code values. Based on this, the role of the prefabricated box fillers was calculated, and in accordance with the effective moment of inertia method a calculation method of section stiffness considering the role of the prefabricated box fillers was proposed.In the fifth chapter, the simplified internal force and deformation calculation method of the concrete fabricated hollow-ribbed floor were studied, and modified on the basis of considering the role of the prefabricated box fillers. And the applicable calculation of the actual project was brought forward. In order to verify the feasibility of this method, comparative analysis had been made between the calculation method and test results.