Project Type: Underpinning & Repair
Service: Compaction Grouting
Areas of engineered fill and uncontrolled loose rubble fill adjacent to the UNM Press building were subsiding, causing distress to the structure.
A previous repair by another contractor using helical piers to underpin the structure was unsuccessful due to large cobbles and construction debris in the fill that caused the piers to refuse installation after only a few feet of embedment.
Working with engineers, Straight Line developed a grouting plan to densify and establish a stabilized zones along the length south side of the building.
Grout was placed at 56 locations to an average depth of 35 feet, for a total of nearly 250 cubic yards of material. Included were 15 locations set at a 20 degree batter into uncontrolled fill in which 10ft³ of grout per vertical foot was placed.
Cobble and debris fills are difficult to effectively compact using traditional methods, and are difficult to remediate post-construction. Compaction grouting is often the most cost effective solution.