TIME-DEPENDENT RELIABILITY OF EXISTING RC STRUCTURES

The conditional probability of failure of a structure, given that it h as already survived for T years, shows that structural reliability inc reases for service proven structures. Further, construction loads act essentially as proof loads, and so provide a means to detect the prese nce of gross construction errors. The present paper investigates the e ffect of construction error, proof load tests prior to occupation, rea listic construction loads, and dead loads and office floor live loads on the probability of failure of service proven structures. The human reliability analysis (HRA) approach is used to simulate the effects of construction error. Results obtained from a Monte-Carlo computer simu lation analysis showed that up to 50% of failures will occur during co nstruction for reinforced-concrete beams constructed without engineeri ng inspections. This suggests that construction loads act essentially as proof loads; hence, for structures with low live-to-dead load ratio s the adverse consequences of construction error will most likely beco me evident during construction. Nevertheless, engineering inspections is a more effective error control measure.