公路建设项目全生命周期环境影响的多级模糊综合评价

A renovated comprehensive multi-level fuzzy assessment approach to the whole life-cycle environmental impact of highway construction project

为综合评价公路建设项目对区域环境的影响,提出了公路项目全生命周期环境影响的多级模糊综合评价方法。在分析公路建设项目的勘察设计、原材料生产与加工、公路施工、公路运营与养护拟及公路废弃与回收5个阶段环境影响的基础上,建立了多级综合评价指标体系。将公路建设项目全生命周期环境影响分为负面影响较大、负面影响较小、基本无影响、正面影响较小、正面影响较大5个等级,采用改进的层次分析法确定权重,引入模糊数学方法进行综合评价,并以商界高速公路DJN24标段为例加以分析。结果表明,该方法可作为公路建设项目全生命周期环境影响评价的基本方法。

In order to evaluate the impact of highway project construction project on the local environment, this paper puts forward a life-cycle assessment （LCA） approach by applying fuzzy mathematics to highway construction project. The highway life can generally be divided into 5 stages： highway project-construction survey and lay-out, raw material processing, construction underway, operation and maintenance, and last of all demolition and recovery. To make the overview assessment successful, we have established an evaluation index system by analyzing the environmental impact of the highway construction in terms of objectivity, science and integrated principle. According to the general characteristics of the impacts of the highway life-cycle stages on the environment, we have divided evaluation indexes to be included into three levels： the highway life-cycle stages, the environmental impact types, and the environmental impact factors, which can then be divided into qualitative index and quantitative index. As to the quantitative evaluation index score, we have first of all worked out the evaluation results with the single-factor-index method, then determined the qualitative index score directly and independently in accordance with the Delphi-method. As to the highway life-cycle environmental impact, it can also be categorized into 5 grades： the great negative impact, the little negative effect, no impact at all, the little positive influence, and the great positive influence. Based on the improved analysis hierarchy process （IAHP）, a fuzzy mathematics method is adopted to evaluate environment impact of highway construction project. The method we have developed is by nature intuitive and concise as the result of overcoming the drawbacks of the traditional analysis hierarchy process （AHP）, namely, the uncertainty of the importance sequence, the complexity of consistency checking and the difficulties of calculation. For instance, we have successfully applied the method to assessing the DJN24 section of Shang Jie expressway construction project. The result of our evaluation shows that the whole life-cycle environmental impact of this expressway section is relatively severe, and the raw material processing and construction underway stage are particularly severe, which makes it necessary to take essential measures to control the project of the two stages to reduce its negative effects on the environment. Thus, it can be said that the life-cycle assessment （LCA） approach established in this study is qualified for successful assessment of the whole life-cycle environmental impact of highway construction projects.