The climate change adaptation strategies for the railway tunnels project are managed by digital multidisciplinary coordination, or Building Information Modelling (BIM), and the case study is focused on the Taipei Metro (MT) Tamsui–Xinyi Line in Taiwan for the railway tunnel analysis. With increasing climate change impacts (such as flooding, earthquakes, extreme temperature, sea level rise, etc.) on railway infrastructure, BIM offers a transformative approach to enhance resilience. This research integrated six BIM dimensions (2D & 3D models, visualisation, scheduling, cost estimation, and sustainability), involved additional material information with Ansys Granta EduPack v.2021 to measure the expenditure of materials and the carbon footprint, and further applied them to propose adaptation measures for the chosen railway tunnel. This study aims to enhance actions to adapt and mitigate climate change effects on railway tunnels, thereby analysing the negative impact of weather hazards. The climate change adaptation strategies are determined based on the case study, and the integration of expenditure, planning, and greenhouse gas emissions is assessed by implementing BIM. AutoCAD Revit v.2021 and Navisworks 19.4 are the virtual simulation tools for design coordination and scheduling for climate risk assessments. The results demonstrate the feasibility of BIM in managing adaptation projects and enhancing asset circularity at the end of life, showcasing its potential for improving efficiency. This study is the world’s first to contribute to enhancing infrastructure management by implementing the advanced capabilities of BIM to develop detailed resilience strategies for railway tunnels.

The recovery and reuse of salvaged products and building materials from existing structures is an essential practice in sustainable construction and environmental conservation. This process, often referred to as building deconstruction or architectural salvage, involves carefully dismantling buildings to preserve reusable materials. It offers numerous benefits, including significant environmental impact reduction, economic advantages, and historical preservation. Environmentally, it reduces the amount of construction and demolition debris in landfills, conserves natural resources by reusing existing materials, and reduces the carbon footprint by decreasing the need for new materials, thus reducing emissions from manufacturing and transportation. Recovery and reuse involve several steps. It begins with assessment and planning, where a detailed site assessment is performed to identify salvageable materials. A deconstruction plan is then developed that details the steps and methods to safely dismantle the structure. During the deconstruction phase, the building is carefully dismantled, starting from the top down, using manual labour and specialised tools to preserve the materials in good condition. These materials are then separated into categories such as steel, timber, concrete, bricks, etc. Next, the salvaged materials undergo cleaning and processing, making them ready for reuse. Proper storage and distribution are crucial to preserve the integrity of materials. However, practice faces challenges such as labour intensity, risks of contamination from hazardous materials such as asbestos and lead paint, fluctuating market demand, and ensuring the quality and safety of reused materials, which may require certification and compliance with building codes. The present chapter starts with aspects of pre-demolition/deconstruction audit that involves the collection of information about the materials and elements that will be recovered and continues with the evaluation of reusability of materials, mainly with steel, timber and concrete, structural components, entire primary and secondary structure.

Circular Manufacturing (CM), understood as CE strategies adopted in manufacturing, takes a key position in decoupling industry growth from environmental impacts. To achieve a transition into circular economy in construction, a clear view on the state-of-the art is crucial. Construction materials such as concrete, cross-laminated timber or steel have an environmental impact during their production and circularity is not always given. Knowing that the design phase of a product defines a big part of its overall environmental footprint, this chapter discusses CM principles and most commonly pursued CM strategies for steel, concrete and timber. Effects and impacts on buildings and eventual challenges are discussed. Furthermore, Additive Manufacturing (AM), as a possible key driver of circularity is analysed. The reduction of material use is identified as key driver in order to reduce material flows, however structural safety and durability needs to be assured. The design and mixture of construction products and materials itself together with an efficient design process in the projects are essential pillars of CM. Prefabrication, modular construction as well as DfD and DfA are key principles that can be achieved with all the analysed construction materials but are more widespread in steel construction today.

Steel sheet piles are used for retaining walls. Due to their modularity, they can be easily installed and extracted after their service life. After their first use, they can be either directly recycled or reused several times and then recycled. The reuse of steel sheet piles allows to avoid new production and thus CO₂-emissions for their production, reducing the environmental impacts per use. In temporary works, like construction pits, the reuse of sheet piles is common practice. Also, for certain permanent projects, there is no disadvantage in using second-hand sheet piles. This paper shows, on the basis of two case studies the best practice for reuse of sheet piles. The environmental impacts for a temporary project in Germany are discussed based on a Life Cycle Assessment for the sheet piling tonnage. Over the life cycle of the steel, 1,535 t of CO₂-eq are emitted. Reuse of the sections saved 79% of greenhouse gases. For a dyke reinforcement in the Netherlands, the project owner partly chose second-hand sheet piles to reduce the environmental impacts of the infrastructure project.

Infrastructure constitutes one of the largest global consumers of construction materials and a major source of embodied carbon emissions. Despite growing momentum toward a circular built environment, deep foundations and retaining structures remain domains in which circularity principles are insufficiently implemented, even though their potential is considerable. This paper examines how steel sheet piles - modular, reusable, recyclable, and increasingly optimised through digitalisation - provide a practical pathway with regards to a part of the 9R framework for reducing environmental impacts across the full life cycle of infrastructure assets. Refuse is addressed by structural health monitoring opportunities. Reduce is outlined through a Life Cycle Assessment showing that permanent sheet pile walls can achieve substantial CO₂e reductions when compared with conventional alternatives. The potential of structural optimisation using products with enhanced efficiency is analysed. Reuse and refurbish is examined by presenting an industrialised reuse model enabled by rental and refurbishment, offering multiple use of sheet piles and carbon savings. Finally, recycle is addressed by analysing how different steel production routes influence overall climate performance. Overall, the findings highlight the essential role of advanced circularity considerations for the decarbonisation in infrastructure.