中文摘要：

根据工程实际，充分考虑规范规定的约束条件和各项技术标准要求，建立了建筑结构优化模型。并提出一种离散变毓结构优化设计的进退搜索算法与标准遗传算法结合成混合遗传算法，既发挥了进退搜索算法高效、局部搜索能力强的特点，又发挥了遗传算法全局性好的特点。算例结果表明，这种混合遗传算法收敛快、精度高，优于标准遗传算法和进退搜索算法：是兼二者之长，弃二者之短的高效的理想优化方法，可以直接用于多种建筑结构的优化设计。

英文摘要：

On the basis of the practical structure design of engineering, the constraint conditions that the norm stipulates and the demands of various engineering standards were sufficiently considered, and a model of structural optimization with discrete variables was derived. Moreover a hybrid genetic algorithm （HGA） composed of the forward-and-back searching algorithm （FBSA） for structural optimization with discrete variables and the standard genetic algorithm （SGA） is proposed in the paper, taking their advantages of powerfully local searching capability of FBSA, as well as the global searching capability of genetic algorithm （GA）. The results by exemplification show that HGA, as an efficient optimal method having the advantages of both SGA and FBSA without their disadvantages, is superior to either one. It can be applied to optimal design of various engineering structures.