Anderson Tailings Impoundment Area 2021-2022 Stage B Construction

The Challenge

This project entailed the new construction and raise/extension of water retaining dams, drilling and blasting of a new spillway, installation of foundation concrete within the new spillway, and the closure of a temporary spillway.

All dam structures included the simultaneous installation of a low-permeability fill (LPF) core with rock shells and sand/gravel filters on undulating and fractured bedrock. The bedrock required hydro excavation and detailed cleaning with hand-operated tools prior to placement of slush grout and dental concrete in bedrock cracks, fissures, or irregularities.

Our Solution

In restricted placement areas adjacent to structures and/or bedrock, hand-operated compaction equipment was used to ensure proper bonding of materials. All rock materials were drilled, blasted, and processed within an existing and undeveloped quarry on site while the sand materials were screened and hauled from an offsite source. Compliance with consultant specifications, a stringent quality control program for materials and compaction testing, and effective water management were critical during construction. Overall length of the dams constructed was approximately 1,500 metres with over 180,000 cubic metres of material moved over two years.

The initial stages of the new spillway construction and closure of the temporary spillway followed a detailed sequencing plan to ensure all owner and consultant specifications were achieved. Rock bolt reinforcement was installed in the new spillway prior to concrete placement. Frequent meetings and open discussions were important to ensure the necessary containment elevations and water control structures were in place throughout the transition process. Sigfusson Northern’s Civil and General Contracting divisions worked together to complete this portion of the work scope.

Project Specs

Location: Snow Lake, Manitoba

Description: Clearing, Pit Pre-Strip, Haul Roads, Plant Site Earthworks & Dam Construction

Completed on: October 2022