Navigating Unforeseen Utility Conflicts in Microtunneling

Abstract

This paper examines a microtunneling project disrupted by an unexpected Bell 360 utility conflict, offering insights into lessons learned and strategies that ensured successful project delivery. Bell 360 Utility is a vital component of Bell Canada’s fiber optic network, providing high-speed and secure connectivity across the country. It supports essential services, including those for financial institutions and emergency operations. During construction, the contractor, while installing a sewer across railway tracks, encountered Bell 360 Utility conduits at an unanticipated depth, halting microtunneling operations. The conflict emerged when the utility owner’s representative informed the contractor that the daylighted utility, initially assumed to be Bell 360, was an abandoned line. Environmental Infrastructure Solutions Inc. (EIS), Trisan Construction Limited (Trisan), Ward and Burke Construction Limited (Ward and Burke), Halton Region (Halton), and Bell collaborated to redesign the sewer alignment, lowering it to avoid the conflict. This complex process involved retrofitting shafts through sub-excavation and underpinning, with Bell permitting tunneling near their conduits under stringent protective measures. This paper also discusses the benefits of securing railway permits during the design stage for invasive utility verification as well as protective measures for microtunneling near critical utilities. Additionally, it underscores the importance of collaboration among owners, contractors, and stakeholders to address unforeseen utility challenges, maintain project schedules, and mitigate cost impacts. This case study provides practical guidance for managing utility conflicts in microtunneling projects, highlighting proactive utility verification, effective teamwork, and innovative construction solutions for successful outcomes. Figure 1. Project Overview