TRENCHLESS RENEWAL OF WATER MAINS BENEFICIAL TO BOTH THE EXISTING WATER MAIN AND THE ASPHALT PAVEMENT

摘要

How many times have we witnessed a newly installed street pavement be prematurely excavated to repair anunforeseen water main break? Why do road crews wait over a year before installing the final asphalt layer on theroadway after a new water main installation? Should trenchless technologies be preferred over open cut replacementto increase life expectancy of the new pavement? Is public perception and political responsibility important to theutility manager? These issues and questions are often used in the decision process to choose the best method toeither replace or renew a deteriorated water main while at the same time considering the life cycle of the roadway.Like many North American cities, the city of Dollard des Ormeaux has completed and put in place an AssetManagement Program for its water, sewer and roads infrastructures. This Program allows the EngineeringDepartment to target the water mains that need to be renewed and the streets that need repaving. For the latter case,the ensuing inspection of the water and sewer infrastructures under these streets has led to the structural renewal ofthe water mains under them.Today, many water utilities work closely with city road departments to efficiently schedule their construction workand to achieve the best design possible for both the water main and the new pavement. For the past ten years, theCity of Dollard des Ormeaux has been using structural cured in place liners to renew their water mains and hasconstantly saved money therefore optimizing each dollar spent on infrastructure renewal. This paper will present,with the help of examples, the decision criteria used by the City of Dollard des Ormeaux to choose and prioritize therenewal of their water mains and also discuss how sidewalk and street paving considerations often impact theirwater main renewal priorities.