Utility Trench Restoration: Strategies and Performance in Low-Volume Urban Roads

Trenching through existing asphalt pavements is a necessity for the installation and maintenance of utilities in most urban areas. This paper will outline expected and observed performance from differing trench methodologies, and provide strategies for decreasing wasted material and improving standards for trench restoration to minimize ground disturbance in residential areas. Drawing on historical information and collected data from pavement condition assessments performed on trenched pavement sections of different ages, the analysis looks to highlight performance characteristics based on strategy from a cost and environmental perspective, and explore asset management practices for improving timings and extent of works. This study was conducted jointly with the City of Mississauga and the Region of Peel in an effort to maximize the efficiency of their Watermain Replacement Program. A data-set including twenty-one (21) roads with existing completed trenches at varying stages of their life-cycle along with eight (8) control roads (similar traffic loading and subgrade conditions) was used to develop a performance model for evaluation. Findings of this study will be discussed, focusing on strategies and data that apply broadly to all types of utility trench cuts, but focus most readily on pavement performance in low traffic urban sections, as well as life-cycle cost analysis with special consideration to the sensitivity to material cost and volume.