关键词: 服役框架结构, 增层, 可靠性评估, 时变, 动态可靠性指标

Abstract: Based on the time-dependent load acting on the frame structure of a building in service and the resistance to it, an argument is set out that the time influence on adding a storey to the building must be taken into account. A dynamic reliability assessment is done for adding a storey onto the frame structure of a building in service, including such influencing factors as the carbonization of concrete, corrosion of reinforcements, reduction in size of cross-sections and strength reduction of concrete and reinforcements. A time-dependent conclusion is therefore drawn that adding a storey onto the top of such a building is feasible if the assessment is qualified. Moreover, the results of the assessment mentioned above are in good accordance with TAT program, thus showing the correctness of argument as set out.