|
|
| Portfolio > Geostructural Engineering > Geostructural Project Detail
|
First Union Commons
Location
Charlotte, North Carolina
Client
Structural Preservation Systems
Services Provided
Geotechnical Exploration
Design of Micropile Underpinning and Tieback Anchors for Foundation Support
Design of Rock Anchors for Excavation Support
Rock Slope Stability
Review of Subcontractor Bracing Design
Foundation Inspection of Footings
Inspection of Underpinning Measures
Project Overview
The First Union Commons building is located in the heart of Charlotte, North Carolina. The excavation for the new structure required cuts of about 30 feet below the surrounding road grades; thus, temporary support systems including H-Pile and Lagging as well as rock bolts and soil nails were required to maintain the surrounding areas. The foundations for this structure were ultimately supported on spread footings supported directly on the exposed rock. Where necessary, rock bolts and anchors were used to resist uplift and shear forces.
Schnabel provided geotechnical engineering recommendations for foundation support, and review of temporary excavation designs by contractors. Of particular interest on this project, was a parking garage immediately adjacent to the proposed building. The First Union Commons building wall was located within two feet of this structure, resulting in foundation elements within inches of one another. The difficulty was that the lowest floor of the First Commons was to be 15 to 30 feet below the foundation of the existing garage. Schnabel designed a system of micropile and high capacity tendon anchors to resist movements of the existing foundation, along with soil nails and rock bolts beneath the foundation to allow a vertical excavation along the edge of the foundations.
Micropiles were installed from inside the structure and consisted of seven-inch diameter steel casing with a design capacity of 160 tons. The anchors had capacities of 75 to 150 tons. With the excavation support complete, foundation installation for the First Union Tower was successfully completed.
|
|
|
|
|
|
|
 |
|
|
|
| Geostructural Engineering Portfolio
|
|
|
|
|
|
|