This project involved the removal of an existing culvert and replacement with a Bolt-a-Plate arch culvert (3660mm x 1520mm x 28142mm) placed at a 39 degree skew to an existing resource road.

The scope of work included:

• construction of bypass road and installation of temporary bypass bridge,
• water isolation using a sheet pile coffer dam and dewatering equipment,
• removal of existing culvert and reconstruction of the stream channel,
• installation of arch,
• construction of headwall and wing walls using GRS backfill,
• GRS road fill, road surfacing, and establishment of environmental controls.

The site was excavated below the historic channel and the creek reconstructed using a boulder layer with smaller material washed in to lock boulders in place. Scattered boulders roughened the channel to slow water and encourage natural flow. The arch was placed on galvanized base channel directly on the compacted boulder surface. Alternating layers of geosynthetic fabric and compacted fill provided backfill, contained by GRS headwalls and wing walls. Soil anchors and wick drain was used to secure the arch to the soil mass and provide drainage as required.