Abstract
Bending moment of the slab caused by a load of a heavy machine under demolition work is usually defined less than allowable moment for temporary loading. The number and arrangement of tube supports are determined to meet the condition. If the plastic deformation of a slab is estimated with accuracy, the reasonable floor support system can be proposed. In this report, the results of measured axial forces of the supports in a 2 way slab are described, and the reasonable support system is proposed.