Achieving sustainability in underground construction through innovation

This paper looks at possible innovations to reduce the environmental impact of underground construction. For example, the concrete and steel reinforcement in sprayed concrete linings are two of the largest contributors to the embodied carbon dioxide of tunnels and underground spaces. Improvements can be made by either replacing materials or changing the design. However, substituting materials and components for 'greener' ones offers only limited gains. Adopting new designs offers the greatest advances but, like all innovations, these face opposition due to their lack of performance data, codes and standards. To improve the sustainability of underground construction, clients need to take a more open approach to innovative methods and products that have lower environmental impacts.