CASE STUDIES
PROJECTS HIGHLIGHT
1. Sunshine Valley — Shallow-Cover Culvert Rehabilitation
THE CHALLENGE
A 3.0m diameter CSP culvert in Sunshine Valley, BC had reached end of structural service life — advanced corrosion, standing water in the invert, and significant section loss across the full wall. At only 0.6m of cover, shallow burial amplified live load transfer directly to the culvert wall and eliminated any tolerance for surface disruption. The road above had to remain in service throughout. Conventional replacement required full closure, earthworks, and a location with no viable detour.
HOW QIS SOLVED IT
QIS applied SprayRoq® SprayWall® via robotic and confined-space spray with liner thickness engineered for shallowcover elevated live load per MOP 145 Design standards. The robotic system delivered consistent DFT over the full 35m run without repeated confined-space entries. Installed thickness exceeded the calculated minimum to account for freezethaw cycling and dynamic loading. The small environmental footprint was key in a ecologically sensitive environment .
THE OUTCOME
35m culvert structurally rehabilitated — zero excavation, fast return to service
Shallow-cover elevated live load addressed with engineered liner design
Road above remained in service throughout — minimal surface disruption
Return to service within 30 minutes of lining completion
Structural liner acts independently of host pipe — fully-deteriorated design condition met
>50-year design service life
2. Skeena deteriorated Culvert Renewal
THE CHALLENGE
The project involved a deteriorated culvert, installed in the 1970s, with a length of 18 meters and a diameter of 1.2 meters. This culvert was crucial as it facilitated the passage of accumulated water from three creeks beneath a railway line, directing it towards the sea. Over the years, the culvert suffered from significant corrosion and abrasion, leading to its deterioration and posing a risk of collapse. The challenge was to rehabilitate the culvert without disrupting the continuous operation of the railway, as halting train services was not an option.
HOW QIS SOLVED IT
To address the problem, the following steps were taken:
Grouting: Approximately 1000 pounds of non-shrink grout was installed to:
Lift and align the settled outlet.
Stabilize the soil under the inlet.
Fill all voids from the 8 to 4 o’clock positions along the bottom of the culvert for its entire length.
Spraywall Structural Liner Installation:
Material: 3.2 sets of Sprayroq’s Spraywall structural liner were supplied and installed in the culvert beneath the railway.
Thickness: The liner was applied at a thickness specified in the stamped engineered drawings, following the high-build protocol of 710 mils (18 mm).
Application: Spraywall was applied to provide a continuous, seamless lining, ensuring long-term structural integrity and protection against further corrosion and abrasion.
Spraywall Properties:
Durability: Spraywall is known for its high durability and resistance to corrosion and abrasion, making it ideal for rehabilitating deteriorated culverts.
Seamless Application: The material forms a continuous, seamless lining that prevents water infiltration and further deterioration.
Quick Curing: Spraywall cures quickly, minimizing downtime and allowing for rapid project completion without disrupting railway operations
THE OUTCOME
The rehabilitation project was successfully completed with the following outcomes:
Structural Integrity Restored: The culvert’s structural integrity was fully restored, eliminating the risk of collapse and ensuring safe passage of water from the creeks.
Minimal Disruption: The project was executed without any disruption to railway operations, maintaining the continuous flow of train services.
Extended Lifespan: The application of Spraywall significantly extended the lifespan of the culvert, providing long-term protection against corrosion and abrasion.
Cost-Effective Solution: The use of non-shrink grout and Spraywall proved to be a cost-effective solution, avoiding the need for a complete culvert replacement.
