Metal Pipe Sealing

Challenge:

A highway contractor extending a box culvert as part of a road widening project had to install a temporary bypass culvert due to high volume tidal flows.  A 96″ CMP bypass pipe was installed by open cut through roadway to bypass adjacent box culvert.  Due to shifting backfill material (on-site sand), the pipe joints became misaligned, causing leaks that overwhelmed adjacent dewatering wells.  This prevented complete dewatering of the box culvert.  

The misaligned joints also caused the backfill material to erode into the pipe, compromising the integrity of the adjacent roadway, which was still in use.

Limits: 

The work was located under a 6-lane primary road, so all work to seal pipe had to be completed without disturbing the roadway surface or traffic flow.  

Speed as important; the box culvert had to be used for handling the tidal flows while the bypass pipe was repaired.  This shut down work on the box culvert.

Solution:

CJGeo performing polyurethane grouting to fill voids around and stabilize a 96" corrugated metal pipe culvert in Virginia Beach, VA for metal pipe sealing.High density polyurethane grouting to fill voids around pipe and seal joints to return pipe to tidal flow bypass ability.  Polyurethane grout was chosen because it is economical, and can be either injected or spray applied.  Injection was required on this project for sealing the joints and filling voids outside of the pipe.  Spray application was required for sealing the various penetrations through the pipe wall.  These penetrations included a 12″ water line and various stormwater pipes.

Result:

CJGeo mobilized two polyurethane grouting crews, who void filled around the pipe by injecting material through the walls, and free spraying polyurethane to seal off the cuts in the pipe for an intervening DIP utility pipe.  CJGeo’s metal pipe sealing solution returned the pipe back to its original function of an intact bypass pipe, allowing construction to proceed.  No roadway closures were required as a result.