Dempsey Case Study
Challenge
Saber was called in to stabilize two office buildings in Aliso Viejo, CA. The buildings, located on a hillside, had settled up to 3 inches. The geotechnical soil study concluded that distress to the existing structures was the result of long-term localized settlement of artificial fill soils under the buildings, possibly aggravated by moisture infiltration from the planters next to the buildings. The settlement resulted in tilting of the concrete floor slabs in both buildings and separation of the joint at the column line on one of the buildings.
Solution
For the stabilization project, Saber excavated the soil to the bottom of the foundation, prepared the footings and installed retrofit foundation brackets. For vertical support we hydraulically drove PP350 push piers to approximately 64 feet at intervals of about 6 feet. For lateral support we installed HA 150 galvanized helical anchors with a hydraulic-powered, rotary-torque drive. To address the issue of the poor soil fill, Saber drilled 5/8-inch holes through the slab within a grid pattern and injected more than 12,000 pounds of PolyLevel® structural grade polymer approximately 65 feet in from the rear of each of the buildings and across the entire length. At completion, both buildings were stabilized, alleviating any concerns over further sinking or deterioration.
Project Summary
DeBerry Engineering Geotechnical Engineer:
