Construction over Voids
2020
CROWSNEST PASS - ALBERTA - Canada
RIVERSDALE RESOURCES
GRASSY MOUNTAIN MINE ACCESS ROAD
Problem
Wood PLC. was working on a design of a new access road over a previous mining activity for Riversdale Resources. After a geotechnical investigation, they encountered a void and needed a reinforced structure that would provide temporary support to allow time to create a permanent solution in the event a void migrates up towards the road. Maccaferri was approached in this reference. The design size of void was 1m in diameter and approximately 1-2m deep. The road area over the void is approximately 10m wide and 120 m in length.
Solution
Wood PLC started working with this upcoming mine in early 2019 with geotechnical support. The project was located 40 km east of Crowsnest Lake. Wood identified where the road passes over an area of former mine workings, where there was an increased likelihood of a void being present. In order to minimize the cost and reduce the pavement section, Maccaferri proposed using a layer of ParaGrid 150/05 in cross and machine direction to achieve 150 KN/m strength in both directions with a non-woven geotextile as separator underneath. Along with ParaGrid, MacGrid EG40 was used in two layers above the ParaGrid at 0.33m spacing.