Inclusion of environmental impacts in life-cycle cost analysis of bridge structures

Civil engineering structures can induce various environmental problems during their lifetime. In this paper, the life-cycle environmental impacts of structures, including the emissions to air, water and land, are quantified by environmental cost, and are considered as a part of indirect cost in the life-cycle cost (LCC) model. The computation of environmental cost based on the pollution prevention measures is presented. Using the environmental fines and taxes on various pollutants the environmental costs of construction materials, energy, transportation, and construction equipment are calculated. Structural type selection of a bridge structure is carried out based on the environmental cost-incorporated initial cost. The environmental cost-incorporated LCC model is applied in the life-cycle cost analysis (LCCA) of steel bridge girders. Hurdle discount rates are implemented on future environmental costs. Uncertainties arising from the direct cost and environmental cost are analyzed. The effects of different types of environmental cost discount rates are discussed.