Experimental Study On Punching Shear Resistance Of Steel Tube Concrete Slab-column Connection With Drop-panels

Slab-column structure is widely used in office buildings,shopping malls,libraries and other civil buildings due to its simple structure,low building height and convenient construction.The drop panel is important for punching shear capacity.The research team has developed a steel-concrete composite slab with a space steel pallet,which has high punching shear strength and built-in pallet to make the space layout flexible and beautiful.Through experiments and theoretical analysis,the effect of the space steel pallet on the punching shear capacity were studied,providing a reference for the popularization and application of the connection structure and the revision of relevant codes and standards.1)Six steel-concrete composite slab-column mid-node specimens with space steel pallets(including one comparison specimen)were designed and fabricated.The column is a concrete-filled steel tube column.The space steel pallet includes steel pallets,connection plate and constraint plate.The test parameters include the size and position of the space steel pallet,the opening of steel pallet and the length of connecting plate.The ultimate bearing capacity,failure pattern,crack development,strain curve of steel bar and concrete under the influence of the parameters are observed.Punching shear capacity increases with the increase of the size of the space steel pallet.Further,increasing the length of connection plate and the opening of steel plate have a significant effect on improving the punching bearing capacity.Compared with ordinary specimens,the punching bearing capacity is increased by 20.37% and 22.04%,respectively.2)Based on GB50010-2010,ACI 318-14,Eurocode 2 code and related literature,a calculation method for the punching shear capacity of steel-concrete composite slab-column joints with space steel pallet is proposed.The accuracy of three formulas is verified by comparing calculation results with experimental results.According to the Chinese code and the European code,the average error of the calculation formula is less than 5%.This calculation method can provide a theoretical reference for further optimizing the design structure and application promotion of space steel pallet.Figure 84;Table 20;Reference 51.