Evaluation of structural safety considering limit states of floor slab in actual buildings

摘要

This paper investigates real conditions for existing floor slabs constructed int he last fifteen years in Japan, and calculates a reliability index #beta#. The factor governing a floor slab's ultimate limit state is reinforcing bar yield point. The factors defining serviceability limit state are maximum crack width, long-term deflection, floor vibration (caused by human activity) up to the limit of human comfort, etc. Limit state live load is calculated and compared with the design load. Results show that the maximum live load doesn't differ with the kind of use, but real live load and safety index do. The investigated floor slabs are safe enough, but are insufficient in terms of serviceability. The structural designer must maintain a balance between competing criteria.