The Tale of Two Cities and a Large Diameter Deteriorated Pipe with In-Line Geometric Transitions Continued….

Abstract

At last years No-Dig North 2024 conference in Niagara Falls, Ontario, GEI Canada Consultants Inc. (GEI) presented on how we overcame significant constructability challenges to identify and prepare detailed designs for rehabilitation of the 1,500mm Lakeshore Sanitary Trunk, a 1,524mm bitumen steel pipe bridge crossing Etobicoke Creek and shallow 1,090mm x 1,524mm and 990mm x 1,524mm concrete box conduit and circular 1,524mm RCP sewer with inline transitions in size and shape, supported on concrete bearing piles and spanning the border between the Cities of Toronto and Mississauga. The Contract for construction was awarded to Michels Canada in the sum of $11,8M (CAD). Construction for rehabilitation of this critical sanitary trunk sewer infrastructure, including installation of full length structural CIPP liners within the circular sewers; grouted in place GRP segmental panel sliplining of the box conduit and transitions and semi structural spray applied MH lining commenced in November 2024 and will be completed in July 2025. This paper will document how, working with the Contractor, Michels Canada, GEI and the Region of Peel, were able to adapt to changing and unforeseen conditions, to manage and mitigate the risks associated with rehabilitation of a shallow sewer with limited access, high flows and no redundancy to implement the design and achieve the desired project objectives of restoring structural integrity and extending remaining useful life by a minimum of 50 years.