Retaining Wall Stabilization

Block Retaining Wall Stabilization, Pittsburgh, PA


Commercial building downspout pipe at the top of a dry stack block retaining wall failed, causing roof water to be discharged behind the wall for a period of approximately four years. Rain water washed the fines out of the backfill material, which caused the larger stones to be suspended by the geotech grid tie back material, which pulled the wall in towards the building.

The facility’s owner repaired the downspout leader, and needed to then stabilize the wall against further inward movement and deterioration by replacing the eroded material.


CJGeo proposed performing polyurethane grouting behind the wall to fill voids. Polyurethane grouting allowed for providing lateral support to the wall itself, and also relieve the tension loading of the geogrid, which was pulling the wall inwards.


A CJGeo polyurethane grouting crew then installed a combination of single component polyurethane and plural component polyurethane behind the wall to fill voids and stabilize the wall against further movement. The repair was completed in a day, for significantly less cost than an alternative proposal the owner had received for stabilizing the wall using grout.