Ground Anchor Proof Testing and Lock-Off Checklist

Definition: Ground Anchor Proof Testing and Lock-Off guides QA teams to apply the approved load schedule, measure movement and creep, and verify lock-off load transfer without covering anchor installation activities.

Apply calibrated load schedule and record displacement at defined intervals.
Validate capacity, stiffness, and load transfer before structural reliance.
Capture readings, photos, signatures, and approvals per project specifications.
Interactive, commentable checklist with export and QR code verification.

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Checklist

Ground Anchor Proof Testing and Lock-Off is the controlled process used to demonstrate that installed anchors meet required performance before they are relied upon. This checklist focuses on proof testing, lock-off, and load transfer confirmation, and excludes installation tasks. It aligns with common geotechnical anchor practices, including lift-off checks, creep measurement, and displacement monitoring using calibrated gauges or LVDTs. You will apply the approved load schedule, record time-displacement data, assess creep, and verify the lock-off load is transferred to the anchor head within tolerance. By following this process, you reduce risks of underperformance, misalignment, gauge error, and unsafe reactions. The outcome is a verifiable, traceable record showing that each anchor meets the acceptance criteria per approved project specifications and authority requirements. Start in interactive mode to tick items, add comments for variances, attach photos and calibration certificates, and export your completed record to PDF/Excel with a secure QR code.

Use this checklist to execute the approved proof load schedule with calibrated equipment, capture time-displacement readings, evaluate creep, and document lock-off load transfer. It supports transparent QA and timely engineer acceptance for each tested anchor.
Practical instructions help you align the jack, verify reaction adequacy, zero displacement instruments to an independent datum, and maintain consistent timing at each hold. The workflow reduces errors linked to gauge drift, air in lines, and unstable references.
Interactive online checklist with tick, comment, and export features secured by QR code.
Complete documentation is built-in: anchor ID, calibration certificates, photos of setup, load and movement logs, creep plots, lock-off results, and signatures. Export standardized reports to accelerate approvals and maintain a defensible audit trail.

Pre-Test Verification

1. Confirm anchor identity, readiness, and documentation before testing.
2. Verify anchor ID, location, and status match drawings; confirm grout cure and stressing authorization per approved project specifications and authority requirements. Evidence: tagged anchor photo, ITP/permit reference, supervisor signature.
3. Review the approved load schedule, hold durations, acceptance criteria, and contingency actions in a pre-task briefing. Evidence: toolbox talk record with attendee signatures and dated briefing photo.
4. Check calibration of jack, gauge, and load cell; confirm certificates are current per project requirements. Evidence: attach calibration certificates, serial numbers, and photo of instrument IDs.
5. Confirm reaction frame/beam capacity and seating, bearing plates, and grillage stability against sliding/uplift. Evidence: setup photos and engineer/competent person acceptance signature.

Equipment Setup

6. Mount hydraulic jack concentric with tendon axis using a spherical seat; check alignment with a straight edge or laser. Acceptance: visible coaxial alignment. Evidence: close-up photos and alignment check record.
7. Install displacement instrument (dial gauge or LVDT) to an independent reference frame; zero reading before loading. Acceptance: stable zero for 60 s with no drift. Evidence: photo and zero reading log.
8. Bleed air from hydraulic lines and set relief valve per manufacturer instructions. Acceptance: smooth pressure rise without chatter. Evidence: maintenance log entry and supervisor initials.
9. Mark tendon and wedges with paint or tape to observe slip and seating movement. Acceptance: marks visible in photos. Evidence: macro photo showing reference marks.
10. Establish synchronized timekeeping for readings; verify stopwatch/clock matches device time. Acceptance: time variance ≤ 1 s between devices. Evidence: timestamp screenshot photo.

Load Schedule Execution

11. Apply seating load and initial cycle(s) as specified to settle the system. Acceptance: movement stabilizes between cycles per schedule. Evidence: load-displacement entries and cycle notes.
12. Increase load in defined increments to the specified proof load, holding at each increment for scheduled durations. Acceptance: pressures/loads match targets within tolerance per specs. Evidence: reading sheet and gauge photos per increment.
13. Record displacement at specified time intervals during each hold (e.g., initial, 1, 2, 5 min as scheduled). Acceptance: consistent timing achieved within ±5 s or per specs. Evidence: time-displacement log.
14. At proof load, maintain the hold and record time-displacement series for creep evaluation. Acceptance: no sudden jumps; stable readings per schedule. Evidence: creep table and instrument photo at proof load.

Creep Measurement and Acceptance

15. Calculate net creep excluding elastic recovery per approved method. Acceptance: creep within project-specified limit. Evidence: calculation sheet or auto-generated report with formula reference.
16. If movement exceeds limits or is non-linear, pause test and notify the engineer. Acceptance: hold condition maintained pending instruction. Evidence: escalation note, photos, and engineer direction attached.
17. Unload per schedule to identify elastic recovery; capture displacement rebound at defined times. Acceptance: recovery trend sensible and repeatable. Evidence: unload curve entries and plot.

Lock-Off and Load Transfer

18. Set wedges and lock-off at the specified load; release jack smoothly to transfer load to the anchor head. Acceptance: lock-off load within tolerance per specs. Evidence: gauge photo at release and recorded lock-off load (kN).
19. Perform lift-off check by re-engaging the jack to pick up the anchor; verify measured lift-off equals target within tolerance. Evidence: lift-off reading (kN), photo, and acceptance tick.
20. Inspect wedge seating and reference marks for slip; confirm no unintended movement after lock-off period per schedule. Evidence: after-lock-off close-up photos and observation log.

Documentation and Demobilization

21. Complete the test report: load schedule, readings, creep calculation, plots, and conclusions. Acceptance: all mandatory fields completed. Evidence: generated PDF/Excel attached with QR identifier.
22. Update anchor register with ID, date, proof load, lock-off load, and acceptance status. Evidence: register entry screenshot and responsible person signature.
23. Remove test equipment and restore the work area; reinstate temporary protections as specified. Evidence: demobilization photos and housekeeping checklist signed.
24. File calibration certificates, permits, and engineer approvals in the project QA archive. Evidence: document links, version control ID, and QA manager sign-off.

Plan the Proof Test for Reliable, Defensible Results

A successful ground anchor proof test starts with disciplined planning. Confirm the approved load schedule, acceptance criteria, and reporting format so the crew knows exactly what to capture. Use calibrated hydraulic jacks, pressure gauges, or load cells to read force in kN, and set up an independent reference frame for displacement using a dial gauge or LVDT. Concentric alignment through a spherical seat minimizes parasitic bending that distorts readings. Reaction beams or frames must be rated and properly seated on bearing plates to avoid settlement during holds. Establish synchronized timing for all observations; consistent intervals make creep assessments credible. Finally, hold a short briefing, show the anchor ID and test limits, and agree the escalation path if creep or slip exceeds limits. Planning protects safety and quality while reducing rework, schedule slips, and disputes with stakeholders.

Confirm load schedule, acceptance, and reporting format upfront.
Use calibrated force measurement; record serials and certificates.
Zero displacement gauges to an independent, rigid frame.
Maintain concentric alignment to limit bending effects.
Brief the team and define escalation for exceedances.

Execute the Load Schedule and Measure Creep Consistently

During execution, increase load in defined increments, holding at each stage for the specified duration. At each hold, record displacement at consistent time stamps to develop a clear time–movement curve. At proof load, maintain the hold and continue timed readings for creep evaluation; calculate net creep in accordance with the approved method so elastic recovery is not double-counted. Watch for non-linear movements, step changes, or unstable gauge behavior; these can indicate seating, grout defects, or reaction movement. When unloading, capture rebound to verify elastic behavior and to support stiffness calculations. Accurate, consistent timing across all anchors improves comparability and speeds acceptance decisions by the engineer.

Hold at each increment per the approved schedule.
Record displacement at consistent, predefined time stamps.
Calculate net creep using the approved method.
Investigate non-linear or step changes in movement.
Document rebound during unloading for stiffness checks.

Lock-Off, Verify Load Transfer, and Close Out Documentation

After acceptance at proof load, set the wedges and transfer load to the anchor head at the specified lock-off value. Confirm the transfer using a lift-off check: re-engage the jack and verify the measured lift-off matches the target within the tolerance in the project specifications. Inspect reference marks for slip and ensure the head remains stable for the observation period. Then finalize reporting: attach calibration certificates, photos of alignment and gauges, time–displacement tables, creep calculations, and plots. Update the anchor register with proof load, lock-off load, and acceptance status. Collect digital signatures from the site supervisor and engineer to close the test and archive records in the QA system.

Set wedges and release to specified lock-off load.
Verify load transfer with a documented lift-off check.
Check reference marks to rule out unintended slip.
Compile plots, certificates, and signatures in one report.
Update the register and archive with version control.

How to Use This Ground Anchor Proof Testing Checklist

Preparation: gather the approved load schedule, test rig, calibrated jack, gauge or load cell, displacement instrument, reaction frame, spherical seat, safety gear, and housekeeping materials. Confirm permits and access, and brief the team.
Open the interactive checklist on a tablet or phone. Enter anchor ID, location, and date. Attach calibration certificates and pre-test photos to the first items.
Progress through items in order. Tick each step as completed, add comments for variances, and capture photos of gauges, alignment, and marks directly in the form.
During loading and holds, input load (kN), time stamps, and displacement readings. Use the comment field to note anomalies such as reaction movement or air bleeding.
After lock-off and lift-off verification, upload plots or auto-generate them if your system supports it. Review completeness; unresolved comments must be addressed before sign-off.
Export the completed, commentable record to PDF/Excel. Share with stakeholders and embed the QR code to secure report authenticity in printed copies.
Sign-Off: obtain digital signatures from the supervisor and engineer, distribute the report, and archive it in the project QA system with version control.

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Ground Anchor Proof Testing and Lock-Off

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Sofia Romero Sofia Romero

Dec 06, 2025

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FAQ

Question: What is the difference between a proof test and a performance test for ground anchors?

A proof test checks each production anchor against specified criteria by applying an approved load schedule, recording displacement and creep, and verifying lock-off. A performance test typically uses additional load stages and longer holds to characterize behavior. This checklist covers proof testing and lock-off only, excluding installation tasks and extended performance testing.

Question: How should creep be measured and evaluated during proof load holds?

Use an independent displacement instrument (dial gauge or LVDT) referenced to a rigid frame, record movement at consistent time intervals, and compute net creep per the approved method. Compare against project-specified limits. Avoid touching the setup during holds, and flag non-linear or step changes for engineering review.

Question: What actions should I take if movement exceeds limits at proof load?

Pause the test at the current hold, maintain safe conditions, and notify the engineer. Record all readings, capture photos, and document potential causes such as reaction movement, misalignment, or air in lines. Await direction per approved project specifications and authority requirements before proceeding or retesting.

Question: How do I verify that the lock-off load has been correctly transferred to the anchor?

After setting wedges and releasing the jack to the target lock-off load, perform a lift-off check by re-engaging the jack and noting the load at pick-up. Acceptance is that the measured lift-off matches the target within the tolerance defined in the approved project specifications.

Question: Which records are mandatory to attach to the proof test report?

Include calibration certificates, anchor ID and location, photos of setup and alignment, load and displacement logs with time stamps, creep calculations, plots, lock-off and lift-off results, signatures, and approvals. Export the complete package to PDF/Excel and secure it with a QR code for authenticity.