Sustainable Bridge Design

The ever-increasing traffic demands, coupled with deteriorating condition of bridge structures, present great challenges for maintaining a healthy transportation network. The challenges encompass a wide range of economic, environmental, and social constraints that go beyond the technical boundaries of bridge engineering. Those constraints compound

Sustainable design of infrastructures has become a major matter of study since the recent establishment of the Agenda 2030. This paper provides a systematic literature review on the use of multi-criteria decision making techniques used so far for the sustainable design of bridges. Special attention is put as well on how the reviewed studies assess the sustainable performance of bridge designs along their life cycle from the economic, the environmental and the social perspective. Although SAW and AHP are recurrently used in the sustainable assessment of bridges, the analysis of the most recent articles show that the application of TOPSIS and PROMETHEE techniques are gaining increasing relevance for such purpose. Most of the studies focus on the research of the construction and the maintenance stage of bridges. However, a need for further analysis is identified when it comes to the assessment of the impacts resulting from the End of Life cycle stage of bridges from a sustainable point of view. The use of intuitionistic and neutrosophic logic have been detected as emerging alternatives to the fuzzy approach of decision making problems.

The work consists of two interrelated parts. The first one presents general issues relating to sustainable development. There are examples of the road investments, in which the problems arising from the lack of a general approach to environmental principles and consequently sustainable construction occurred. In the second part, on the examples of culverts and bridges, selected technical cases are discussed. The aim of the paper is to characterize the inconsistencies appearing during the bridge design process and maintenance in accordance to environmental categories. Several examples of the road-bridge investments carried out in the last decade have created the basis to formulate some opinions and questions. The difference between the approach of bridge engineers and that of environmental ones to the concept of animal transition is shown on the grounds of implemented technical and environmental standards. The existing problems are of dual nature, the first group being very general aspects i.e. concerning the concept of ecology, while the other one involves detailed tasks, e.g. shaping the image of a bridge. Several questions of great significance have been formulated and addressed to ecologists. The answers are indispensable for bridge engineers to solve technical aspects of the proper, sustainable design of environment-friendly bridges. Last but not least, the suggestion to use bridges as places for monitoring the environment in their surroundings is presented. This research work might be crucial for further good cooperation of bridge engineers and environmental ones.

One of the latest trends in engineering is sustainable design, which is designing so that resources are available for many generations to come. Sustainable design considers the ecological, economic, and socio-cultural environments and works to balance all three. Sustainable bridge design is still in development, and clear standards and recommendations have not been formalized as they have in building design. The U.S. Green Building Council's Leadership in Energy and Environmental Design (LEEDTM) Green Building Rating System evaluates sustainable building design by awarding points based on measurable criteria. The LEEDTM rating system deals with buildings, but a similar system could be developed that would apply to bridge design. This report proposes a rating system for sustainable bridge design based on current practices and emerging technologies. Three bridges (either new or under construction) were rated using the system and the results are presented. Also discussed are steps and obstacles for implementation.

Essential infrastructures such as bridges are designed to provide a long-lasting and intergenerational functionality. In those cases, sustainability becomes of paramount importance when the infrastructure is exposed to aggressive environments, which can jeopardise their durability and lead to significant maintenance demands. The assessment of sustainability is however often complex and uncertain. The present study assesses the sustainability performance of 16 alternative designs of a concrete bridge deck in a coastal environment on the basis of a neutrosophic group analytic hierarchy process (AHP). The use of neutrosophic logic in the field of multi-criteria decision-making, as a generalisation of the widely used fuzzy logic, allows for a proper capture of the vagueness and uncertainties of the judgements emitted by the decision-makers. TOPSIS technique is then used to aggregate the different sustainability criteria. From the results, it is derived that only the simultaneous consideration of the economic, environmental and social life cycle impacts of a design shall lead to adequate sustainable designs. Choices made based on the optimality of a design in only some of the sustainability pillars will lead to erroneous conclusions. The use of concrete with silica fume has resulted in a sustainability performance of 46.3% better than conventional concrete designs.

The focus of this research is to develop a framework for more sustainable design and construction processes for new bridges, and sustainable maintenance practices for existing bridges. The framework includes a green rating system for bridges. The green rating system is divided into three sections, which are design, construction and maintenance. The three sections are further divided into various criteria. For each criterion the description, intent, and requirements have been established. The requirements were established after reviewing various industry standards. The Delphi survey was conducted at MDOT divisions to assign point values to sections and the criteria. The results of the Delphi survey and scorecard of the rating system are shown in the relevant appendix and/or sections. The certification levels for the rating system are established to categorize sustainable bridges. A bridge can be categorized as Non-Green, Certified, Green, Total Green, and Evergreen, depending on the total score obtained by the project. LCA and LCCA guidelines are also developed to support the sustainability of bridge projects. LCA guidelines include the steps to calculate GHG emissions in a bridge project. It was made an inventory of construction materials and equipment that can be used in bridge projects, and found their emission factors in literature, historical databases, or by using computer tools. Certain products emit less GHG compared to conventional products. Recycled materials such as fly ash, blast furnace slag cement, high performance concrete, and steel produce much less emissions than traditional materials. Sustainable products are listed along with their emission factors and can be used to calculate GHG emissions. LCCA guidelines include steps to calculate the life cycle cost of bridges.

Sustainability is the defining challenge for engineers in the twenty-first century. In addition to safe, economic, and effi-cient structures, a new criterion, sustainable, must be met. Furthermore, this new design paradigm–addressing social, economic, and environmental aspects–requires prompt action. In particular, mitigation of climate change requires sustainable solutions for new as well as existing structures. Taking from both practice and research, this book provides engineers with applicable, timely, and innovative information on the state-of-the-art in sustainable structural design. This Structural Engineering Document addresses safety and regulations, integration concepts, and a sustainable approach to structural design. Life-cycle assessment is presented as a critical tool to quantify design options, and the importance of existing structures–in particular cultural heritage structures–is critically reviewed. Consideration is also given to bridge design and maintenance, structural reassessment, and disaster risk reduction. Finally, the importance of environmentally friendly concrete is examined. Consequently, structural engineers are shown to have the technical proficiency, as well as ethical imperative, to lead in designing a sustainable future.

The chapter is a voice in the discussion concerning sustainable bridge development. Nowadays, the term has rather been abused, and therefore the presented approach refers to these elements of design, construction and maintenance of bridges-with regard to their role in transport and social life-which have been present in bridge construction for a long time and can be easily incorporated into the concept of sustainable bridge construction. Sustainable development, sustainable construction and so on are multidimensional. In the considered bridge construction area, looking at construction processes as interfering with the environment and which could and should be restricted is a new element. Nevertheless, other proven constructional solutions and technologies are characterised by their reliability. Assuming that the constructed bridges are to serve the next two or three generations of users, we can try to extrapolate current technical conditions on the next 30 or 60 years, id est, up to three generations. We can do it if we know and are able to critically assess the history of bridge construction. Following this reasoning, the history in question is referred to in this paper, although rather subjectively and with the omission of numerous important personalities and technologies as well as instructive failures due to the publishing limitations.

Having designed more than 75 K-12 school projects, and with a long-standing commitment to sustainability and a passion for architecture, Alan Ford is perfectly positioned to present this illuminating collection of sustainable school projects from around the world. Designing the Sustainable School is a compendium of ideas illustrating how some very talented architects and committed facility planners are meeting the challenge of creating better schools for the 21st century. They are creating schools that are eco-friendly, embody high-performance design principles, are rich in architectural character, and enhance the health and well-being of students and teachers. The projects represent a wide range of design solutions, aesthetics, location, and scale, ranging in size from the Aga Khan Award-winning three-room schoolhouse in Burkina Faso by Diebedo Francis Kere, to the 2500-student, 260,000-square-foot high school in Santa Ana, California by LPA Architects. Each of the 45 featured projects is presented with an overview of the components of the high-performance "tool kit" employed by architects to achieve sustainable design goals. Collectively, these demonstrate the breadth of tools that today's architects can employ to build a sustainable future for our children.