A Proposal on Equation of Punching Shear Strength for Considering Depth of Compression Zone in Donut type Biaxial Hollow Slab

The hollow slab has hollow spheres within the slab. The hollow slab system is known as one of the effective slab system whichcan reduce self-weigth of slab. But the present code does provide computation method for the punching shear strength of solidslab. On the other hand hollow slab does not suggest in present code. also, punching shear formula was proposed that punchingshear resistance factor is compression zone. because of the hollow sphere, hollow slab is expected to different depth of compressionzone against the solid slab. So, punching shear strength of the hollow slab is propose punching shear strength equation throughusing depth of compression zone.??? ????????? 2011?????? ????????????(???) ?????? ?????? ????????? ?????? ???????????????