基于随机占优度的高拱坝施工方案优化研究

Construction scheme optimization for high arch dams based on stochastic dominance degrees

高拱坝施工方案优化需要综合考虑多个随机指标,属于随机多属性决策过程。当前针对高拱坝施工方案优化的研究,基本上没有完整考虑各指标的随机特性,降低了方案优化结果的准确性。同时,在当前随机多属性决策中,指标融合权重多是人为设定,难以客观表达不同指标之间的重要性。针对以上问题,本研究提出了基于随机占优度的高拱坝施工方案优化方法。根据仿真计算结果,得到各方案的施工进度指标的概率分布;基于随机占优理论及随机占优度,得到各方案对之间的随机占优度;将PROMETHEEⅡ方法进行改进,采用CRITIC方法建立各评价指标权重,并进行指标融合,得到各施工方案优先排序。工程实例表明,此方法可以在考虑施工进度指标随机性的情况下,实现高拱坝施工方案的优化。

In construction scheme optimization, it is essential to comprehensively consider several random evaluation indexes, and this constitutes a problem of stochastic multiple attribute decision making. Previous studies on construction scheme optimization for high arch dams have not fully considered the random characteristics of these indexes, and therefore resulted in low accuracy in optimization. The existing methods that involve stochastic multiple attribute decision making, normally use artificial specification of the index weights and hence are not able to describe objectively the relative importance of different indexes. This paper presents a new method of construction scheme optimization for high arch dams based on stochastic dominance degrees. Through numerical simulations, we have obtained the probability distribution of construction progress indexes for all the construction schemes and calculated their stochastic dominance degrees using the stochastic dominance theory. Then, a priority order of these schemes can be achieved by calculating the weights of these indexes with CRITIC and fusing the indexes with a modified PROMETHEE II method. A case study shows that this method is effective in optimization of construction schemes for high arch dams featured with randomness in construction progress indexes.