Chilliwack Fire Department, Chilliwack B.C.
Subgrade soils for this site consisted of silty sands and sand with silt. The Rapid Impact Compactor was used as a remedial ground improvement option, with the expectation that the upper 10 to 15 feet would be treated, with a cone depth of about 12 inches. However, typical cone depth (depth of impact crater) was on the order of 3 feet, with an improvement in the blow count from 12 to 20 at a depth of 30 feet! Average overall ground deformation (subsidence) resulting from the RIC process averaged 18 inches. As a result, the building's foundation design was modified, resulting in a significant cost savings for the project.