Study On The Deformation Performance Of Reinforced Concrete Floor Slabs Under Concentrated Load

The floor slab is the main component of buildings,and it is also the main component of the structure system which bears the vertical load and transmits the horizontal load.Most of the engineering design is based on the floor under the uniform load as the condition of the floor deformation computations;The present Code adopts the method of equivalent uniform load to deal with the concentrated load and local load,which can not accurately reflect the influence of the concentrated load on the floor deformation.With the attention of people to the requirements of buildings use,the use of load caused by the impact of plate deformation is gradually highlighted,especially in large supermarkets,multi-storey plant and the operation of large wheeled transport equipment on floor slab during construction.How to evaluate the effect of its concentration on the deformation of the floor,is an urgent problem to be solved.In this paper,the calculation theory and method of plate under concentrated load are introduced,considering the influence of load position,plate thickness and plate-span ratio,the deformation test of full-scale reinforced concrete slab under concentrated load was carried out,and two concentrated loads were considered simultaneously.The numerical analysis model of the test plate is established by using the finite element software,the difference between the numerical analysis result and the test result is compared,and the reliability of the model is verified by contrast analysis.Through the calculation model of the plate under the concentrated load under different conditions,the influence of the load position,the thickness of the plate and the ratio of the length to the span on the deformation of the reinforced concrete slab is compared and analyzed.The research results show that: under the action of concentrated load,(1)the farther the loading point is from the center of the plate,the smaller the maximum displacement is;(2)the closer to the edge of the plate,the greater the change of the vertical deformation of the reinforced concrete slab is caused by the moving of the load position;(3)when the single point loading point is not in the center,the maximum deformation position of floor will deviate from the position of the load to the center of the plate;(4)plate thickness increases,plate deflection decreases;(5)the vertical deformation of the plate increases with the short side size fixed and the length-span ratio increasing.