Grout Pipe & Bulkhead Installations — Highway 407 Culvert Relining

The problem. Culverts under the Highway 407 corridor were rehabilitated by sliplining — new carrier pipes installed inside deteriorated host pipes — leaving an annular space that had to be filled completely along the full length of each crossing. Grouting a long, buried run under a live highway leaves no room for guesswork: every injection, vent, and drain point has to be planned before the bulkheads close the pipe ends.

The repair. Watertight bulkheads were constructed at both ends of each culvert. Behind them, 2-inch PVC grout injection pipes were installed in 10-foot sections, staged at the 5%, 25%, 50%, and 75% points along the run, with a vent pipe at the high end and a drain pipe to manage water. Grout was injected from the high end, working point to point, with the staged pipes and vent providing positive confirmation that the annulus filled progressively from end to end.

The result. A completely filled annular space, verified by the staged injection and vent sequence rather than assumed — the standard we apply to every buried fill where nobody can see the grout go in. The staged grout-pipe and bulkhead layout documented on this project remains the template for how we set up culvert relining fills today.

Project photos