LRDR-LES Foundation Drilled Test Shaft Piles, Pile Load Testing and Reporting

USACE Alaska

LRDR-LES Foundation Drilled Test Shafts, Shaft Load Testing and Reporting

Location: Clear, Alaska

Value: $2,000,000

Completion: October 2017

Scope of Work:

  • Drilling test shafts, testing and reporting

STG Pacific was awarded a contract to construct two drilled shafts, load test the shafts, and test data reporting. In addition, STG Pacific reviewed the 95% design documents for constructability of the Long Range Discriminating Radar (LRDR) Foundation.

STG Pacific teamed with sister company, STG Inc. who provided cranes and operators and Malcolm Drilling. To facilitate drilling operations, STG removed the drill spoils and assisted in set up for toe grouting and Osterberg cells (O-cell) testing. We constructed two drilled 48-inch shafts with reinforced concrete, O-cell, and testing instrumentation. We tested the drilled shafts using the O-cell method, monitor stresses, and record and graph movement versus force applied. Our testing confirmed the engineering design and demonstrated that the permanent foundation shafts would outperform the design.

After providing shaft test results, the STG Pacific team participated in the 95% LRDR-LES Foundation Design Conference. We shared our expertise and lessons learned about phasing, constructability issues and drilled shaft installation, providing significant value to stakeholders and demonstrating an effective review process for the future work.

Performance Highlights

  • Project was substantially completed in less than 60 days after award, for participation in the design conference per contract requirements
  • Successfully demonstrated that the shafts would exceed performance requirements