Dan MacDonald, P.Eng (co-author)
GeoMontreal (October 2013)
The City of Surrey selected a Sierra® Vegetated Slope System as the structure of choice for the approach walls leading up to this cast in place, pile supported bridge structure.
This paper will discuss the use of the vegetated slope system inclined to the horizontal at 69 degrees as the primary facing element for these approach walls. The facing of this slope system is comprised of welded wire forms to assist in construction, along with a synthetic structural wrap comprised of Tensar Biaxial Geogrid, Erosion Blanket, and Topsoil to form the vegetated facing. The prime structural soil reinforcement consists of Tensar HDPE Uniaxial Geogrid. These slopes are up to 5 meters high, and used in conjunction with rip-rap and sheet piles, effectively form the southern riparian zone of the Serpentine River at this location. The structure crosses over the Serpentine River which is a sensitive spawning and rearing habitat for trout and salmon, and is located immediately downstream of the Tynehead Fish Hatchery. The paper will focus on the design methodology, ease of construction, with an additional emphasis on the environmental benefits for this sensitive infrastructure application.