A Critical Review of the Sustainability of Multi-Utility Tunnels for Colocation of Subsurface Infrastructure

Abstract

Multi-utility tunnel (MUT) have received increasing attention as an alternative method for installing subsurface infrastructure for the distribution of electricity, telecommunications, water, sewage and district heating. MUTs are described as a potentially more sustainable technology than conventional open-cut excavation (OCE), especially if the entire life cycle of these cable and pipe networks is taken into account. Based on an extensive review of the academic literature, this article aims to identify and critically examine claims made about the pros and cons of using MUT for the placement of subsurface infrastructure. Identified claims are mapped, and their validity and applicability assessed. These claims are then analyzed from a sustainability perspective, based on the three sustainability dimensions and a life cycle perspective. The results show that a variety of advantages and disadvantages of using MUTs for subsurface infrastructure are highlighted by the articles, but several of these are without any empirical support. When some form of empirical support is presented, it usually comes from case-specific analyses of MUTs, and the applicability in other MUT projects is seldom discussed. Economic performance is the sustainability dimension that has received the most attention, while environmental performance has not been analyzed in the reviewed literature, which is a major limitation of the current knowledge. In summary, the knowledge about the sustainability performance of using MUTs for subsurface infrastructure is still limited and incoherent. In order to increase the knowledge, this article points out the importance of new case studies, in which the sustainability consequences of using MUTs for subsurface infrastructure are mapped and evaluated by combining both quantitative and qualitative assessment methods.

Pancosmorio (world limit) theory of the sustainability of human migration and settlement in space

“…The result is a drop in terraform specific threshold disruption resistance and terraform specific threshold disruption resilience of throughflows in the network. This equates to the current sustainability struggle documented in human cities on Earth (e.g., Morello et al, 2000;Pope et al, 2009;Bergman et al, 2022;Zucaro et al, 2022). If we do things the same way in space as we have done on Earth, the struggle will be similar.…”

Sustainability performance of multi-utility tunnels : Sustainability assessments for furthering knowledge and understanding

“…The latter is also the owner of the MUT in Vallastaden. A pipe-based and a cable-based utility owner were selected based on the potential differences in economic benefits that Bergman et al (2022) identified.…”

“…After all the mentioned pros and cons of using MUT instead of OCE were identified in the transcribed material, a categorization was used to sort the claims. The categorization is based on Bergman (2022), where the difference between MUT and OCE was described as 1) additional underground construction, 2) colocation in an indoor environment and 3) access without excavation. When all the pros and cons were coded and categorized, the last step was to further analyse each of them with the aim of identifying which actor or actors were impacted.…”

“…These studies often present MUT as a more sustainable alternative to OCE for managing the city's subsurface infrastructure: "The utility tunnel is potentially one of the most sustainable urban underground infrastructures and must, therefore, be taken into account in urban planning…" (Cano-Hurtado and Canto-Perello, 1999 p.388) "The use of urban utility tunnels (UUTs) is, without a doubt, the most sustainable solution to face a changing future as a result of the digital revolution in which we live." (Valdenebro et al, 2019 p.39) The earlier research on the sustainability of the MUT consists, however, of rather scattered studies focusing on different specific aspects or dimensions of sustainability performance (e.g., Canto-Perello and Curiel-Esparza, 2001;Hunt et al, 2014), and there is not any research that holistically assesses the MUT's sustainability performance (Bergman et al, 2022). This makes it difficult to identify limitations and gaps in current knowledge and leads to difficulties in deciding which aspects should be particularly focused on in future research to improve the understanding of the MUT's sustainability performance and thus be able to strengthen the sustainability claims.…”

How to Guarantee the Sustainable Operation and Maintenance of Urban Utility Tunnels? From the Perspective of Stakeholder and the Whole Life Cycle

“…Urban utility tunnels (UUTs), also known as multi-purpose utility tunnels, multi-utility tunnels, utility corridors, common ducts, or underground municipal pipe galleries, are more sustainable than traditional infrastructure projects [1][2][3][4]. Incorporating municipal pipelines and cables (electricity, telecommunications, water supply, sewage, gas, heating, etc.)…”