The Plasticity Analysis of the Cast-in-Situ Prestressed Concrete Hollow Slab

The cast-in-situ prestressed concrete hollow slab is a new type of slab. It combines the unbonded prestressed and the cast-in-situ concrete technology and it has the advantage of long-span, light weight and excellent performance of isolated voice. But the research on the performance of the cast-in-situ prestressed concrete is not so more, at present investigation is mainly focused on non-prestressed concrete hollow slab. The plasticity analysis of side supporting and column supporting cast-in-situ concrete hollow slab is introduced respectively. Then the simulation of the two examples are made with ANAYS finite element analysis software, some conclusions are obtained as following: based on yield line theory, the plasticity limit analysis of prestressed concrete hollow slab is reasonable. The plasticity limit load of hollow slab structure is much larger than design value by elastic design method, in the example the plasticity limit load is about four times as the design value. It should reduce the design value of the slab bending moment under meeting the normal using limit state. If the membrane effect is not considered, the reduction factor of bending moment should be 0.8 to 0.9, whereas it should be 0.7 to 0.8.