For construction of the Children’s Hospital South Campus Project, Peirce Engineering designed the required temporary earth and rock support systems for a building excavation up to 72 feet deep along Civic Center Boulevard, the South Access Road, and existing Pennsylvania Hall. Believed to have the city’s deepest-ever building excavation, this project utilized a combination of drilled-in soldier beams, tieback anchors, and timber lagging, along with shotcreted soil nail walls and rock bolts. A later implosion for the demolition of immediately-adjacent Pennsylvania Hall had no effect on the soil nail wall or on a pre-existing, tiedback, soldier beam and lagging wall.