Selection of Sustainable Short-Span Bridge Design in Brazil

Abstract

Owing to the elevated cost of bridges, especially when compared to the cost of roads, their rational design and material selection are fundamental properties to consider when aiming to reduce the environmental impacts and lengthen the lifespan of the bridge. Especially in developing countries, the construction of new bridges (mainly short spanned) is still a necessity, and it is important that these new structures are designed according to all the sustainability parameters, instead of being based only on the construction cost. Thus, the present work aims to study short-span bridges by integrating environmental assessments into the decision-making process. To achieve this goal, three short-span bridge designs, proposed by public organizations in Brazil, are evaluated: Precast concrete bridge, mixed concrete/steel bridge, and timber bridge. In order to allow comparison, the same location and span are considered. The structures are evaluated considering the following quantitative aspects: Cost of construction, assembly and material transportation, lifespan, and environmental impact (measured by the global warming potential, GWP). In addition, some more subjective factors are considered, such as the architecture (layout and appearance) and the user’s sensation of security. The selection is made by the adoption of two multi-criteria decision-making methods (analytic hierarchy process or AHP and Vikor). The results obtained with both methods indicate the mixed concrete/steel bridge as the most adequate alternative. Some additional analysis is performed in order to evaluate the influence of the qualitative aspects, as well as to study the importance of the variations in the costs on the results.

A Review of Multicriteria Assessment Techniques Applied to Sustainable Infrastructure Design

“…15.7% of the reviewed manuscripts (13 papers) deal with the sustainability assessment of bridges. Most of them focus either on the sustainability of bridge deck designs [51][52][53][54][55][56][57] or on the selection of optimal maintenance strategies [58][59][60]. Attention is also paid to the sustainability of different strengthening or repair schemes [61,62] and to the selection of the most sustainable construction method [63].…”

“…It considers the emissions derived from the production of construction materials and construction works, but also from the externalities associated with the construction of infrastructure and its maintenance, such as traffic congestion [61]. While some authors explicitly focus on particular air pollutants, such as carbon dioxide [24,27,30,57,93], SO 2 or NO x [64,70], or general greenhouse gases [31,73], attention is also paid to pollutants emitted to water [79][80][81] when dealing with urban water systems.…”

“…Kripka et al [57] use the AHP method based on Saaty's fundamental scale to determine a normalised score for each of the qualitative criteria considered in the sustainability assessment, namely, architectural value and security sensation. Other studies also base the scoring of qualitative data on such approach, such as [55,60,62].…”

“…COPRAS is recognised to be simple to calculate and, in contrast with SAW, adequate when dealing with both maximising and minimising criteria values [119]. Other MCDM techniques, such as Cost-Benefit Analysis (CBA) [24], Compromise Programming (CP) [61,84], Multiattribute Utility eory (MAUT) [22], Analysis and Synthesis of Parameters under Information Deficiency (ASPID) [64], Distance-Based methods [56], and VIKOR Advances in Civil Engineering technique [57,66], have been marginally applied to assess the sustainability of particular infrastructure designs. Although no systematic relationship is found between the MCDM method applied and the field of assessment or the weighting method used, it is interesting to note that five out of the six publications using COPRAS are focused on the sustainability evaluation of buildings.…”

A Novel Construction Technology for Self-Anchored Suspension Bridge Considering Safety and Sustainability Performance

“…The onsite bridge construction activities can have significant impacts on environment, mobility, and safety [1,2]. The direct and indirect loss of environment and traffic disruptions resulting from the bridge construction can exceed the actual cost of the structure itself [3]. For instance, full-lane closures in large urban centers, or on highways or waterways with heavy traffic volumes, can have a significant economic impact on commercial and industrial activities in the region [4,5]; partial lane closures that occur alongside adjacent traffic can also lead to safety and environmental issues (e.g., extra CO 2 emissions due to traffic detour) [6].…”