【摘要】 文章定义“递阶工程系统”是复杂工程项目的主要工程结构依照功能逻缉关系所构成的层次、分支结构系列。除网络系统外，此类结构系列为结构工程系统的一般形式。文章以二级递阶工程系统为例，提出二种普遍型全局优化方法，其中通过“递级凝聚法”直接形成工程系统整体数学模型的目标函数；通过“Lagrange对偶分解法”建立大系统内部分解与协调的概念，使优化空间高度降维。文章结合算例分析，对二级递阶工程系统的性质和优化机制作了进一步的讨论。在实际工程应用中，文章概念与方法为决策复杂工程项目的最优设防水平、最优投资和总投资的最优分配，提供了严密的分析理论和参考依据。更多还原

【Abstract】 The hierarchical engineering system is defined as a multilevel and branching structural series which is composed of main structures in a complex engineering project by logical relations.This structural series is a generalized form of all kinds of engineering systems except network .Two general optimization methods are proposed in this paper.The global object function of the system is directly formed by a "Hierarchical Condensation Method", and the concept of decomposition and coordination for the optimal subspace of each subsystem are created by a "Lagrange Dual Decomposition Method",which makes the dimension space of the optimization reduced. Cowbined with examples and analysis,the property of the system and the mechanism of the global optimization are discussed in details. In a practical engineering application, the concepts and methods presented in this paper can he viewed as a theoretical basis and a profitable reference for the determination of the optimal fortification level, investment and dispensation of the total investment of a complex engineering project.更多还原