Adopting augmented reality to avoid underground utilities strikes during excavation : a thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy, School of Built Environment, College of Science, Massey University, New Zealand

Abstract

The construction industry constantly pursues innovative methods to improve safety, enhance productivity, and reduce costs and project durations. Augmented Reality (AR) is a promising technology, potentially bringing about transformative changes in construction. AR is a promising technology for visualizing data in construction sites and preventing clashes and accidents. One of its promising applications is in the excavation sector, where accidental strikes on underground utilities pose serious safety risks, delays, and costly damages. However, while AR has gained increasing attention in recent years, its integration into construction practice remains limited. To address this limitation, this research investigates the potential of AR to facilitate identifying underground utility locations through a systematic review, industry engagement, and user-centred experimentation. Initially, a systematic literature review was conducted to explore the current applications of AR in construction safety. This review identified the safety purposes of AR across three project phases: pre-event (e.g., training, safety inspections, hazard alerting, enhanced visualization), during-event (e.g., pinpointing hazards), and post-event (e.g., safety estimation). However, the review also revealed a notable lack of studies focused on AR applications in excavation activities, particularly for underground utility strike prevention. In response, a study was undertaken to understand the needs, expectations, and challenges associated with adopting AR in the excavation sector. 31 professionals from the excavation industry participated in the within-subject experiment, interacting with two AR prototypes, delivered via Optical See-Through (OST) and Video See-Through (VST) devices. The findings indicated a clear preference for AR over traditional methods such as paper-based drawings. Participants showed a preference for VST rather than OST, given their familiarity with VST devices such as tablets. Further, accessibility emerged as the primary barrier to adopting AR within the excavation industry. Building on the literature and industry insights, an experimental study was designed to evaluate the effectiveness of different AR visualization methods in underground utility detection. A within-subject experiment involving 60 participants was conducted to compare four of the most cited visualization techniques for underground utilities: X-Ray, Shadow, Cross-Sectional, and a newly developed Combination method. Drawing on the Theory of Affordances and Task Load analysis, the study found that the Combination and X-Ray visualization methods perform superior to the Shadow. These results provide empirical support for the user-centered design of AR visualization techniques in excavation practice. This research contributes to the fields of human-computer interaction, construction safety, and digital technology adoption by advancing the use of AR for underground utility strike prevention. The study shifts the focus of AR from general safety training to real-time, spatial visualization for excavation, offering both theoretical insights and practical applications. Methodologically, it follows a structured mixed-methods approach, combining literature review, industry engagement, and experimental testing. Practically, it identifies user preferences, visualization methods, and key adoption factors such as usability and accessibility. Overall, this thesis fills the gap between emerging AR technologies and their integration into safer excavation practices.