Research On Theory And Application Of Bridge Environment Impact With Life Cycle Assessment

The rapid growth of the national economy has not only brought about the prompt development of basic construction, but also resulted in increasingly severe environmental problems. According to the World Bank's estimate, China's annual losses caused by environmental pollution take about 10 percent of. GDP. As a large basic construction, the bridge has been bringing a far-reaching impact to the surrounding and even global environment during its life cycle: social impact, ecological impact, aqueous impact, atmospheric impact, etc, which is causing a serious threat to the environmental health and the livelihood of vicinal people. However, the current research about LCA of bridge is still in the exploratory stage, which can not be used to evaluate the bridge's life-cycle environmental impacts objectively and quantitatively. Therefore it has a great significance to make a comprehensive, systematic and scientific assessment on the bridge's life-cycle environmental influence for solving environmental problems arising from the bridge and constituting scientific Countermeasures toward environmental protection.Life Cycle Assessment (Life Cycle Assessment, LCA) refers to through comprehensive and scientific evaluation which is about the entire life cycle( "Being from the cradle to the grave") of products all the environmental impacts to identify its resource consumption and emissions to the environment ,and to evaluate the impact of these consumption and emissions to the environment. Basing on the Southern Taizi Lake bridge of Wuhan City and being on the basis of the LCA, this paper investigates the level and indicators of assessment of bridges life cycle environmental impact by the numbers, proposes a comprehensive evaluation method of environment impact of bridge life cycle, and forms a assessment system of environment impact of bridge life cycle.1. The theory of evaluation on construction's environmental impacts and the environmental factors were systematically studied, and LCA was firstly introduced to the theory of environmental assessment to establish a multi-level, multi-factor model of the environmental impact index. Calculation methods of qualitative and quantitative index have been proposed to realize the quantization of environmental index of LCA, which provide a theoretical basis for the objective, accurate evaluation on environmental impact. 2. Deeply studied the estimate target weight method and its application in engineering, life cycle of bridge to the environment impact assessment methods have been proposed. Combining subjective and objective empower law, the qualitative and the quantitative indicators of life cycle of bridge to the environment impact was analyzed by the numbers. On the basis of the AHP and the Delphi methods, two affirmatory methods of weight about life cycle of bridge to the environment impact assessment were proposed: target distance method and IAHP method. For comprehensive evaluation of life cycle of bridge to the environment impact, the theoretical foundation has been settled.3. Based on LCA, the bridge environmental impact evaluation methods have been proposed innovatively: the multiple indicator comprehensive evaluation method and the fuzzy comprehensive evaluation method, on the basis of the LCA, multiple indicator comprehensive evaluation system and fuzzy comprehensive evaluation system the bridge environmental impact have been formed, comprehensive environmental impact of the Southern Taizi Lake bridge of Wuhan City was evaluated separately by these two evaluation methods, the results showed that: there is a certain negative impact on the environment which the life cycle of the bridge to, however relatively small, and the major negative environmental impact generated in the production stage and the construction stage of the raw materials, the operational stage had no effect on the environment.4. Research on emulation analysis and monitoring of the Wuhan Southern Taizi Lake bridge has been carried out systematically. The Wuhan Southern Taizi Lake bridge adopt a much complicated structure of arch continuous box girder and V-shape pier, whose construction phase is very difficult, and the force condition of each construction phase is not explicit. Therefore, the paper build the common finite element model of The Southern Taizi Lake bridge in Wuhan, predominate the internal forces condition of the worst construction phase, and set up the monitoring control system of the Wuhan Southern Taizi Lake bridge on the spot which ensure the bridge deflection, stress and displacement of key brackets in construction phase Ensure the smooth progress of the construction phase. The paper has very important value to similar bridge monitoring control.Through above study, author proposed the comprehensive assessment method of life cycle of bridge to the environment impact, and formed the assessment system of it. This research effectively solved the impact on the surrounding environment in the life cycle of bridge, and protected the inhabitant's living conditions. It is a significant action to realize the sustainable development of the economy and environment. It has a long run significance to construct the harmonious society and achieve the sustainable development of the national economy.