Abstract Manager

Peatlands remain one of the most challenging environments for infrastructure development because of their high compressibility, low shear strength, and typically saturated conditions. These characteristics present particular difficulties in the Canadian subarctic, where major mineral deposits in regions such as the Ring of Fire cannot be developed without reliable, year-round transportation access. In addition to access roads, mine haul roads constructed across peat deposits must support extreme axle loads, yet practical design guidance for these conditions remains limited in current engineering practice.

In prior research conducted by several of the current authors, three approaches for constructing embankments on peat were evaluated: direct placement of granular fill, full excavation and replacement of peat, and construction of floating embankments reinforced with geosynthetics. That study used RS2 finite element modelling under static loading conditions with settlement limited to 50 mm as a serviceability criterion. Material quantities were incorporated into a cost-benefit assessment considering peat thickness, haulage distance, and seasonal excavation constraints. Results indicated that excavation may be more economical where peat is shallow (less than 1 m), whereas reinforced floating embankments are often the most practical and cost-effective option for thicker deposits.

The present paper builds on previous work by examining the cyclic performance of floating embankments reinforced with geosynthetics. To represent a range of mine traffic conditions, two typical haul trucks are considered: a mid-size truck with a payload of roughly 75–100 tonnes, and a large truck with a payload greater than 200 tonnes. These cases reflect the lower and upper bounds of haulage demand in Canadian open-pit mines.

Finite element analyses are carried out using RS2, to simulate repeated wheel passes. Settlement accumulation and generated pore water pressure are studied for unreinforced roads, roads with single basal, and dual geosynthetics layers. The comparison highlights how reinforcement placement and embankment height influence rutting and long-term serviceability under heavy traffic. A cost analysis will be conducted to assess the impact of incorporating geosynthetics into the design and to identify potential cost savings based on varying granular fill material supply costs.

By linking the static evaluation of the previous study with new cyclic loading analyses, this paper provides a more comprehensive view of road behaviour on peat. The results help define the reinforcement strategies required to maintain mine road performance over time and contribute to the development of practical design guidance for access infrastructure in peatland regions of northern Canada.