The Mechanical Performance Analysis On Slab-column Connection Of The Cast-in-situ Hollow Concrete Floor

The slab-column structure of cast-in-situ concrete hollow floor is a new slab-column system that use cast-in-situ concrete hollow floor after the traditionalgirder floor andGirderless Floor. According to the research results at home and abroad and the actual application of slab-column structure, the mechanical behavior of the slab-column node is critical. Nowadays, the study of slab-column nodes at home and abroad especially the mechanical behavior of the slab-column structure of cast-in-situ concrete hollow floornodes research little, and the mechanical behavior and bearing capacity calculationfor hollow floor plate column nodesis not clear.In this paper,a finite element model is establishedfor finite element analysis and theoretical analysison thebasis of literatures and test. After that, theslab-column nodes’ mechanical behaviorof cast-in-situ concrete hollow floor is studied.Finally,some suggestions of punching hollow floor formula is putted forward.In this paper, the main content of the research is as follows:First, this paper establishes a slab-column nodefinite element model that includes solid floor and hollow floorby using finite element software ANSYS.According to the analysis of the stress nephogram of maximum principal stress and the changes of fracture distribution and development situation, it is known that the slab-column node of solid floor and hollow floor under the vertical load bearing performance have some similarities and differences.Second, this paper changes the longitudinal steel reinforcement ratio, hollow part on the edge of the distance to the column, rib width, hole size, thickness of the floor slab, and researches the above factors on the cast-in-situ concrete hollow floor slab-column node mechanical behavior influence.Finally, this paper compares and analyzes about configuration that do not bent up the steel bar and stirrup slab-column node under the vertical load for the punching shear bearing capacity calculation formula of the influence factor of considerationat home and abroad.As far as our country, on the basis of considering the influence of the ratio of longitudinal reinforcement and depth, it puts forward proposals of the hollow floor punching shear capacity formula, and can provide a reference for engineering design.