简单工程系统抗地震设计全局优化的直接解法

本文定义“工程系统”是工程项目所包括的主要工程结构的集合,“简单工程系统”是其遇灾总损失期望可以直接以显式表为各结构损失期望和系统损失期望之和的工程系统.后者包括串联、并联、串并联和候选系统.本文提出直接利用Lagrange乘子法进行这类系统全局优化的解法.全局优化的目标函数包括系统的总造价和总损失期望,优化变量是各结构的最优设防烈度,约束条件符合现行抗震结构设计规范的原则和规定,特别是考虑了抗震结构的三级设防准则.因此,所提方法是非常合理而又切实可行的.此外,还给出了简单工程系统投资最优分配的计算方法.

GLOBAL OPTIMAL ASEISMIC DESIGN OF SIMPLE ENGINEERING SYSTEMS BY DIRECT OPTIMIZATION METHOD

Engineering system is defined as the set of the chief structures in an engineering project. For a simple engineering system, its total seismic loss expectation may be expressed directly as the sum of the loss expectation of the damages of structures and that of the failure of whole system. Both the total cost and total loss expectation of the engineering system are considered in the objective function of optimization by Lagrange multiplier method. The variables of optimization are the optimal fortification intensities of structures in the engineering system. The multi-failure criterions for aseismic structures are considered in the determination of the loss expectation. The proposed method is rational , practical to use and consistent with the National Design Codes. In addition, the method for deciding the optimal distribution of the investment to structures of the engineering system is given.