In current tunneling and other underground constructions, geotechnical instrumentation and monitoring has become a standard practice which allows for the instant evaluation of the construction impact to validate or adjust design/construction parameters as well as to protect infrastructure and public safety. Among various instruments, robotic total station (RTS) is one of the most effective tools capable of providing automatic, high precision and near-real time monitoring of ground and structure deformation. RTS is primarily known to operate in reflector mode in which the RTS is tracing optical prisms attached to the monitored objects while under some circumstances, installing and maintaining a sufficient number of prisms is not practical due to financial or logistic constraints.
This paper introduces a case study of utilizing RTS in reflector-less mode to monitor ground deformation during an on-going high-profile Sequential Excavation Method (SEM) tunneling project in Canada. The studied project requires continuous monitoring of nearly 500 points across 21 lanes of highway with a fast monitoring frequency, which makes it not practical to install prisms as monitoring points without having a significant impact on the highway traveling lanes or limiting the array of monitoring points. This paper briefly describes the project followed by the explanation of RTS workflow. Then focuses are placed on the design considerations of this unique reflector-less monitoring system and solutions to address challenges during its implementation and maintenance. Finally, selected monitoring results are presented with comparison to other supplemental instruments and RTS camera imaging. The paper is aimed to contribute to the literature on reporting the large-scale use of reflector-less monitoring technique in similar applications, which will become more common due to increasing tunneling activities in urban areas.

Webequie First Nation, located approximately 500 km north of Thunder Bay, Ontario, is developing an all-season road between the community of Webequie and a proposed Ring of Fire mining development around Esker Camp near the Mukutei River, approximately 110 km to the east. The Webequie First Nation Supply Road (WSR) project is the first Indigenous-led environmental assessment in Ontario. Once completed, the WSR will offer year-round movement between the community and the future mine site and will facilitate economic opportunities for the community. This paper presents a description of the terrain analysis and mapping within the proposed route corridor, along with potential aggregate sources and stream crossings, that will guide the identification of an optimal route based on terrain and engineering considerations.

La Première Nation de Webequie, située à environ 500 km au nord de Thunder Bay, en Ontario, développe une route toutes saisons entre la communauté de Webequie et un projet de développement minier Ring of Fire autour d'Esker Camp près de la rivière Mukutei, à environ 110 km à l'est. Le projet Webequie First Nation Supply Road (WSR) est la première évaluation environnementale dirigée par des Autochtones en Ontario. Une fois terminé, le WSR offrira un mouvement à toute-l’année entre la communauté et le futur site minier et facilitera les opportunités économiques pour la communauté. Cet article présente une description de l'analyse et de la cartographie du terrain dans le corridor d'itinéraire proposé, ainsi que des sources d'agrégats potentiels et des traversées de cours d'eau, qui guideront l'identification d'un itinéraire optimal en fonction du terrain et des considérations d’ingénierie.

The Inuvik-Tuktoyaktuk Highway (ITH) in Northwest Territories, Canada was built during winter on ice-rich continuous permafrost with no cuts in the ground to preserve the permafrost foundation. Several high-fill sections were required along the highway to meet vertical geometry specifications. Embankments in Arctic regions are susceptible to deformations due to thawing of the frozen fill material and permafrost foundation at the embankment toes. One high-fill section along ITH was reinforced with woven geotextiles to reduce slope movements. The reinforced section and an adjacent control section were instrumented to monitor slope movements. Terrestrial laser scanning (TLS) was conducted at the research site in June 2018 and June 2019. A real-time kinematic (RTK) survey system was used to measure ground control point (GCP) positions for georeferencing the TLS reconstructed point clouds. Embankment deformations were determined by point cloud comparison. TLS deformations were compared to instrumentation deformation data. This paper presents the methodology and results of the TLS deformation monitoring. Limitations of the technologies are discussed and recommendations for deformation monitoring using TLS are provided.