Shaft Camera Inspection: Verify Sidewalls, Base, and Debris

Definition: Shaft camera inspection for construction QA teams visually verifies sidewall and base conditions and identifies debris in drilled shafts or caissons, excluding NDT analyses, to confirm cleanliness and bearing readiness before concreting.

Visual verification of sidewalls and base cleanliness in drilled shafts.
Mitigates inclusions, weak zones, and post-pour remediation delays.
Deploy downhole camera with lighting, depth marks, video and photo capture.
Interactive, commentable checklist with export and QR code traceability.

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Checklist

Shaft camera inspection provides a direct, visual method to verify sidewall and base conditions and identify debris before concreting. Also known as a borehole video inspection or downhole camera survey, this process focuses on cleanout confirmation, sidewall stability, and bearing surface readiness while deliberately excluding NDT analyses such as sonic integrity testing. Using a high-resolution camera with integrated lighting and depth overlay, inspectors document sloughing, cavities, soft seams, sediment thickness, and foreign objects. By capturing clear evidence at defined intervals, the team reduces risks of inclusions, laitance, and compromised load transfer. The scope is strictly visual: observe, measure with simple tools (marked rod), and document; any structural capacity assessment remains out of scope and must follow per approved project specifications and authority requirements. Use this interactive checklist to standardize preparation, execution, and documentation; tick off steps, leave comments at anomalies, and export your record as PDF/Excel with a QR code for traceable approval.

This checklist standardizes visual verification of drilled shaft sidewalls and base conditions using a downhole camera. It focuses on confirming cleanliness, detecting sloughing or cavities, and documenting debris without employing NDT. Clear pass/fail cues and required evidence reduce ambiguity and accelerate pre-pour approvals.
Interactive online checklist with tick, comment, and export features secured by QR code. The system embeds depth-stamped photos and videos, assigns actions for cleanout, and supports versioned re-inspections so teams can demonstrate timely closure of nonconformances and maintain auditable construction records.
Practical acceptance cues include visibility thresholds, depth encoder accuracy, sediment thickness limits, and coverage requirements across the base. The guidance explains when to pause for water clarification, how to capture anomalies every metre, and how to name and archive media so stakeholders can rapidly review findings.

Pre-Inspection Planning

1. Confirm shaft ID, design diameter, and target depth against latest drawings; record from bore log and layout reference. Evidence: photo of marker board showing shaft ID, design diameter (mm), and planned depth (m). Acceptance: IDs match documents, no conflicting revisions.
2. Verify excavation status: drilling complete, cleanout equipment available on standby, and no reinforcement installed yet. Evidence: supervisor confirmation and timestamped photo of open shaft. Acceptance: safe access confirmed by superintendent prior to camera deployment.
3. Assess water presence and clarity from surface; if submerged, plan lighting and stabilization. Acceptance: ability to resolve 10 mm scale at 1.0 m distance on test shot; else schedule clarification/pump-and-settle.
4. Brief team on scope (visual only; exclude NDT analyses), roles, emergency retrieval, and hold points. Evidence: toolbox talk record with names/signatures. Acceptance: all roles acknowledged, rescue plan in place.

Equipment Setup and Function Check

5. Inspect camera lens and housing; clean with lint-free wipes; verify no scratches or leaks. Evidence: close-up photo of lens before use. Acceptance: lens free of defects; O-rings intact.
6. Check lighting output and beam angle; set brightness to avoid washout. Evidence: calibration photo against a 10 mm/50 mm test card at 1.0 m. Acceptance: features clearly visible without glare.
7. Zero and verify depth encoder against a steel tape. Evidence: encoder reading at 5.0 m equals tape ±0.10 m. Acceptance: deviation ≤ 0.10 m across the check range.
8. Confirm date/time stamp, video resolution ≥ 1080p, storage space ≥ 10 GB, and battery ≥ 80%. Evidence: settings screenshot. Acceptance: all thresholds met before descent.

Access and Safety Controls

9. Establish a 2 m exclusion zone with barriers and signage; secure tripod or boom over the shaft. Evidence: site photo showing barriers and anchor points. Acceptance: no unprotected openings or trip hazards.
10. Fit camera tether and retrieval line rated above equipment mass × 5; verify connections. Evidence: tag photo showing working load limit (N). Acceptance: all connections locked and inspected.
11. Assign a spotter to monitor descent and depth callouts; maintain radio contact. Evidence: names recorded on checklist. Acceptance: continuous communication maintained throughout operation.

Visual Survey – Sidewalls

12. Lower camera at ≤ 0.3 m/s; pause every 1.0 m to rotate 360°. Evidence: still images per metre with depth overlay. Acceptance: continuous video plus clear stills at each metre.
13. Identify sloughing, raveling, or cavities; estimate depth/extent using depth overlay and a scaled reticle. Acceptance: no cavities > 50 mm deep or continuous slough > 25 mm thick; otherwise flag for cleanout or stabilization.
14. Note groundwater inflows, seams, or obstructions that could trap debris. Evidence: annotated photos with arrows and depth. Acceptance: inflows not eroding fines; if jets observed, escalate to engineer.
15. Verify no foreign objects (tools, cables) along the wall. Evidence: clean sweep video segment. Acceptance: zero foreign objects; any found must be retrieved and re-inspected.

Visual Survey – Base and Debris

16. Set camera at base; pan slowly to capture full circumference. Evidence: stitched or continuous video covering 360°. Acceptance: base surface visible without obscuring turbidity.
17. Measure loose sediment thickness with a marked rod adjacent to the camera. Evidence: photo showing gradations (mm) and depth overlay. Acceptance: loose sediment ≤ 50 mm over ≥ 90% of base; else cleanout required.
18. Check for standing water depth and clarity over base. Evidence: rod reading (mm) and visibility note. Acceptance: water condition suitable for concreting per approved project specifications and authority requirements.
19. Confirm absence of foreign objects on base (cuttings bags, tools, wire). Evidence: close-up photos at suspected locations. Acceptance: zero foreign objects; if present, remove and re-verify.

Documentation and Closeout

20. Rename media with convention: Project_ShaftID_Date_Depth(m). Save raw video, stills, and checklist. Acceptance: complete dataset stored in project repository with read access for stakeholders.
21. Summarize findings: sidewall condition, base cleanliness, water notes, anomalies, and required actions. Evidence: signed inspection report with depth-indexed photo table. Acceptance: report approved by superintendent/inspector.
22. If cleanout performed, repeat critical base and affected sidewall visuals to confirm closure. Evidence: before/after comparison images with identical depth overlays. Acceptance: all previous nonconformances resolved.

When and why to use shaft camera inspection

Visual shaft camera inspection is the fastest way to verify sidewall stability and base cleanliness just before concreting. Unlike NDT methods, this approach documents what is actually present—sloughing, cavities, sediment, and foreign objects—so crews can act immediately. It is best used after drilling and preliminary cleanout, before cage placement or tremie setup. The camera’s depth overlay allows findings to be tied to elevations in the bore log, enabling precise directions for targeted cleanout. By setting clear acceptance cues for visibility, sediment thickness, and sidewall integrity, the site can release pours with confidence. If water is present, the inspection helps decide whether to clarify, pump and settle, or proceed with planned methods per approved project specifications and authority requirements. The result is fewer inclusions, reduced rework, and stronger load transfer at the base. Teams also gain a defensible record that supports approvals, dispute resolution, and future audits.

Use after drilling and cleanout, before cage placement.
Tie anomalies to depth with encoder overlay.
Set visibility and sediment limits before inspection.
Decide on water management based on clear evidence.
Capture a defensible pre-pour record.

Techniques, acceptance cues, and common findings

Lower the camera steadily at or below 0.3 m/s, pausing every metre to rotate 360 degrees. In clear water or dry shafts, a 10 mm test card should be readable at 1 m; in turbid conditions, adjust lighting and wait for settlement. Sidewalls should appear continuous with no deep cavities or thick slough. At the base, focus on sediment distribution, protrusions, and foreign objects. Use a marked rod next to the camera to measure loose sediment in millimetres across multiple spots. Typical acceptance cues include a depth encoder accuracy within ±0.10 m, loose sediment ≤ 50 mm over at least 90% of the base, and no foreign objects visible. If cues are not met, stop, direct cleanout, and re-inspect the same depths for closure. Avoid interpreting structural integrity; this checklist is strictly visual and excludes NDT analyses.

Rotate 360° every metre with depth-stamped stills.
Visibility: read 10 mm scale at 1 m.
Depth encoder tolerance within ±0.10 m.
Sediment ≤ 50 mm over ≥ 90% of base.
Exclude NDT; focus on visual conditions.

Evidence management, naming, and approvals

Strong documentation makes approvals fast and auditable. Start by photographing a marker board at the shaft with ID, design diameter, and date. Record continuous video with depth overlay and capture stills every metre and at anomalies. Use a consistent naming convention that encodes project, shaft ID, date, and depth. Store originals in a read-only folder and attach select clips to the inspection report summarizing conditions and required actions. When cleanout is performed, repeat the same views to create before/after pairs. Route the report for digital signatures so responsibilities are clear and time-stamped. Archive the signed report, media, and the interactive checklist export in the project CDE. This provides traceability for client reviews, authority spot-checks, and internal quality audits without ambiguity about what was seen and when.

Capture continuous video plus stills each metre.
Use strict file naming and controlled storage.
Summarize findings with depth-indexed tables.
Obtain digital signatures and archive exports.
Create before/after pairs after cleanout.

How to Use This Shaft Camera Inspection Checklist

Preparation: gather shaft camera with lighting, depth encoder, marked rod, barriers, tripod/boom, radios, PPE (helmets, gloves, high-visibility, eye protection), and cleaning kit for lens. Verify site is ready: drilling done, access safe, cleanout tools available, and scope limited to visual inspection (exclude NDT analyses).
Open the interactive checklist on your device. Start a new record, enter project and shaft ID, and photograph the marker board. Enable time/depth overlay on the camera and confirm storage and battery status.
Tick items as you proceed. Add comments at each anomaly with depth, estimated extent, and required action. Attach photos and short video clips to the relevant steps for evidence.
If acceptance cues are not met (e.g., sediment too thick), pause the inspection, perform targeted cleanout, then re-run the affected depths. Use comments to link before/after media and record closure.
Export deliverables: generate PDF/Excel outputs including checklist, photos, and links to original media. Ensure depth overlays are visible on key frames for review by stakeholders.
Sign-Off: capture digital signatures from inspector and superintendent, share with stakeholders, and archive in the CDE. Verify QR code on the export for authentication and traceability.

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Sofia Romero Sofia Romero

Jan 14, 2026

FAQ

Question: What does a shaft camera inspection verify that NDT does not?

A shaft camera inspection provides direct visual confirmation of sidewall continuity, base cleanliness, sediment thickness, and foreign objects. It does not infer structural integrity or detect subsurface defects like NDT methods. Use it to decide on cleanout and readiness to pour; schedule NDT separately per approved project specifications and authority requirements.

Question: How clear must the water be to perform a reliable inspection?

As a practical cue, the camera should resolve 10 mm markings at approximately 1 m distance without glare. If visibility is poorer, reduce lighting intensity, allow settlement, or clarify per site procedures. If clarity cannot be improved, postpone inspection until conditions meet visibility requirements for credible evidence.

Question: What acceptance criteria should I use for base cleanliness?

Measure loose sediment with a marked rod at several locations. A common visual threshold is loose sediment ≤ 50 mm covering at least 90% of the base, with no foreign objects. Any protrusions or thicker sediment should trigger cleanout and re-inspection, with final acceptance per approved project specifications and authority requirements.

Question: How should I name and store photos and videos from the inspection?

Use a consistent convention, for example: Project_ShaftID_Date_Depth(m)_MediaType. Store the original files in a read-only folder, link key frames in the report, and export the interactive checklist for signature. Maintain traceability with depth overlays and include a QR-authenticated export in the project CDE.

Question: When should the inspection be scheduled in the construction sequence?

Schedule immediately after drilling and initial cleanout, before reinforcement cage placement or tremie setup. This timing lets you identify sloughing or debris while access for corrective cleanout is still straightforward. If cleanout is performed, re-inspect promptly and secure sign-off to avoid delays to concreting.