Robustness of Floor Systems Due to Post-Drilled Holes

Abstract

Most of our attention is focused on serious hazards with rather spectacular consequences, like fire, explosions, earthquakes, and so on. However, this type of event is fortunately infrequent and well-covered by regulations, codes, scientific work, and engineering practice. In practice, we’ve seen a much higher frequency of uncontrolled drilled holes with lower consequences until now. Floor systems are rarely or inadvertently designed to withstand this kind of action; there is a lack of knowledge of which system is the most appropriate in an ultimate limit state or an accidental situation. In this paper, a robustness factor R is defined which reflects the same philosophy as a safety factor and is equal to the ratio of the total reinforcement demand with a certain kind of opening to avoid collapse, and the reinforcement requested without openings. When this factor is equal to 1, the system is very robust and needs no additional reinforcement; however, if it becomes higher than 1, your system becomes sensitive for post-drilled holes at a random location