The Influence Of The Cast-In-Place Floor Slab On Seismic Performance Of Frame Structure

Reinforced concrete frame structure because of its flexible layout, the use of space is large and can be used to partition wall break up a space, and so on a bit of a widely used for residential、office building、classroom building, etc.After the wen chuan earthquake, A lot of building structure present a "strong beam weak column" type, The cause of the structure of the serious damage and collapse, giving people life and property caused a great loss.To explore the main cause of their destruction, found that the cast-in-place floor slab has a significant effect on the yield mechanism of frame structure.In order to have rational knowledge about its failure mechanism, this paper on the floor effect on seismic performance of frame structure is studied.This thesis mainly do the following work:1.This paper introduces the structure after the earthquake, the failure mechanism of the rendered and explore the cause of damage, and eventually found the cast-in-place floor slab’s influence on the beam can’t be ignored.2.Using PKPM software design of a frame structure reinforcement design, Then the reinforcement structure into SAP2000.Three model is set up, respectively is:the model a (pure frame structure); Model 2 (with board structure, not the palette tendons); Model 3 (plate) configuration in the steel, and then the static elastic-plastic analysis3.According to the result of reinforcement in a calculated flexural bearing capacity of intermediate nodes, Then comparing considering and not considering the effects of plate steel plate bending bearing capacity of beam.4.The seismic grade for the frame structure of the secondary bending moment at the end of the increase coefficient of 1.8 and based on this model. According to the results of the current specification design of reinforcement, Will be 30% of the area of the beam end reinforcement configuration to the plate, column reinforcement doesn’t change, plate of reinforcement need to meet the structure reinforcement and the minimum reinforcement ratio.According to this condition model, Finally the static elastic-plastic analysis.Through the above research can get the following conclusion:1. Cast-in-place floor slab can significantly increase the stiffness of the structure, reduce the deformation of the structure, improve the shear bearing capacity of the structure; Plate reinforcement increases the existence of the beam end bending bearing capacity, it will change the yield mechanism of the structure.2. Seismic grade for the bending moment at the end of the frame structure of the secondary enlargement coefficient suspected is too small.6 times on each side of the beam thickness after reinforcement, within the scope of the beam end bending bearing capacity was 1.657 times than that without considering plate reinforcement, if to increase the bending moment at the end of the coefficient is 1.8, the frame structure appears as yield better beam hinge mechanism.3. Will be 30% of the area of the beam end reinforcement is placed in the plate, by the decrease of the flexural bearing capacity of the beam end, structure beam end plastic hinge rotation, only the bottom column and part of a plastic hinge at the end of the floor, but the plastic hinge in stage B-IO-LS (B:a plastic hinge; IO:immediately; LS:life safety)...