中文摘要：

通过对公路施工网络计划优化方法进行分析,建立了符合公路施工网络计划特点的质量-工期-费用的优化模型;利用拥挤度计算和非劣排序,以及精英保留策略的遗传算法,并采用工序染色体编码的方法,缩小了公路施工网络计划优化程序对有效解的搜索空间;通过轮盘赌选择、算术交叉、变异等操作,得到一个Pareto最优解集,供决策者从中选择出最符合实际情况的方案;提出了改进的NSGA-Ⅱ多目标优化方法。通过工程实例,采用改进的NSGA-Ⅱ对施工方案进行优化,利用MATLAB 7.0编程仿真,可获得Pareto的最优解集。

英文摘要：

Through the analysis of network planning optimization method for highway construction,the quality-duration-cost-optimization model with the characteristics of network planning for highway construction was established.The multi-objective optimization method based on NSGA-Ⅱ was put up.The method was GA that using non-dominated sort about crowding distance and elitism strategy.Through chromosome coding based on process,the search space of solution was optimized.Through the roulette wheel selection,arithmetic crossover and mutation operation,the Pareto optimal solution collection,that could allow decision-makers to choose,was got.At last,through engineering examples,this paper confirmed that the optimization method could solve the Pareto optimal solution collection from establishing the optimization model,using MATLAB 7.0 simulation program.