Cast Box-shaped Hollow Slab Calculation Method Of Analysis And Research

The hollow cast-in-place box is a new floor which is forced in two-ways.Compared with other floors,it has great advantages,and it has worked to a certain application in underground area.But because the design theory of the hollow floor cast-in-place box is not perfect now,its advantages are hampered to a certain extent.This text is using of the existing experimental data,in-depth studying of the rib slab design theory, and summing up a formula for the simulation of the bearing capacity of the hollow cast-in-place box,at last analyzing the finite element by making use of the software ANSYS.The main research method of this text is the combining of theoretical analysis and finite element analysis.According to the existing,there could be the hollow cast-in-place box equivalent of a rib slab by the simulation of the bearing capacity.Though the analysis,the main point is amending the equivalent width coefficient in the method of the virtual cross-beam,and summing up a formula for the simulation of the bearing capacity of the hollow cast-in-place box by the simulation of the ultimate load of the hollow cast-in-place box with the virtual cross-beam method and Limit balance method.Meanwhile it analyses and compares the deflection of the rib slab and the hollow cast-in-place box,in order to truly reflect the features of the bearing capacity of the hollow cast-in-place box and real play the advantages of the hollow cast-in-place box.At last it compares the rib slab with the hollow cast-in-place box in the ultimate load and the deflection by making use of the software ANSYS,and it has proved the feasibility of the formula by comparing with the previous theoretical analysis.By the analysis the equivalent width coefficient of the virtual cross-beam methodλ₁=I/I′is amended toλ′₁=I²/I₁I′,and the amended virtual method is named the virtual cross-ribbed beam method,then calculating the ultimate load of the hollow cast-in-place box combining with the limit balance method.Because the calculation results of the ultimate load and the results of finite element analysis are very close,it has proved that the virtual cross-ribbed beam method has some practical value.Meanwhile by comparing the rib slab with the hollow cast-in-place box in the ultimate load and the deflection,we can see that the bearing capacity of the hollow cast-in-place box is higher than the rib slab under the same conditions because of the "mold" at the bottom floor of the hollow cast-in-place box.