基于投资-效益准则的结构目标性能水平

投资-效益准则作为基于性能的抗震设计的一个基本原则,反映了现代结构抗震设计思想的一个重要转变,即从以往只注重结构安全,向全面注重结构的性能、安全及经济等诸多方面发展.讨论了结构目标性能水平的合理描述;根据投资-效益准则,提出了基于结构层间变形失效模式的目标可靠度优化决策模型,并介绍了最优结构设计强度和最优设防烈度;最后讨论了上述3种目标性能水平的特点,得出结构寿命周期总费用评估是3种目标性能水平优化决策中均需解决的问题,而且最优可靠度强调结构个性,最优设防烈度是强调结构共性的结论.

Cost-effectiveness criterion based structural target performance levels

The cost-effectiveness criterion is one of the most important principles of performance based design, and demonstrates the important change in the modern seismic design, in which more attention is paid to the performance, safety and economy of the structure. The rational expression of the target performance levels is studied, and the formulations of the optimum reliability of structural story drift are proposed according to cost-effectiveness criterion. The concepts of the optimum design strength and the optimum design intensity are also introduced, and compared with the optimum reliability. The solution is obtained that the evaluation of life-cycle cost is the common problem faced by these three kinds of target performance levels, and the optimum reliability stresses the structural individuality and the optimum design intensity stresses the structural generality.