Thermal Integrity Profiling (TIP) Checklist for Foundations

Definition: Thermal Integrity Profiling (TIP) checklist for deep foundations guides builders, testers, and inspectors to install wires, record heat signatures, identify anomalies, and document acceptance, explicitly excluding CSL methods.

Install thermal wires and log concrete heat to prove integrity.
Detect necking, inclusions, cage offsets, and poor cover early.
Use calibrated loggers at 1–5 minute intervals, compare traces by depth.
Interactive, commentable checklist; export results with QR code.

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Checklist

Thermal Integrity Profiling (TIP) provides a reliable, non-destructive method to assess drilled shafts and bored piles by using the concrete’s heat of hydration. This checklist covers thermal profiling from wire installation through heat signature recording, anomaly identification, and acceptance. It focuses solely on TIP and explicitly excludes CSL, ensuring a single clear procedure for deep foundation quality assurance. By placing temperature sensors along the reinforcing cage and logging at tight intervals, TIP reveals necking, inclusions, soft bottoms, and cage misalignment as characteristic temperature deviations. The process improves early detection, reduces costly rework, and documents foundation integrity in SI units suitable for design and authority records. Users will plan the test, install and verify wires, configure calibrated data loggers, capture pour timestamps, analyse traces by depth, and issue an acceptance decision per approved project specifications and authority requirements. Start interactive mode to tick tasks, add comments and photos, and export consolidated reports to PDF or Excel with a secure QR code.

This TIP checklist standardizes deep foundation integrity testing by guiding teams through preparation, instrumentation, logging, and evaluation. Clear tolerances, SI units, and evidence requirements help prevent data gaps, protect instrumentation during placement, and ensure traceable results that support confident foundation acceptance and reduce rework risk.
The method captures the concrete’s heat of hydration using evenly spaced thermal wires strapped to the reinforcing cage. Consistent peak temperatures and similar curve shapes across channels indicate uniform cross-section, while sustained cold zones or asymmetric gradients by depth highlight probable necking, inclusions, or cage offset for targeted investigation.
Interactive online checklist with tick, comment, and export features secured by QR code.
Deliverables include time–temperature plots by depth, variance summaries, calibration records, photos, and pour logs. The package links measurements to pile IDs and logger serials, enabling rapid review by the contractor, consultant, and authority, then digital sign-off per approved project specifications and authority requirements.

Pre-Test Planning

1. Confirm TIP as the sole integrity method for this scope; explicitly exclude CSL in the test plan. Evidence: approved plan referencing TIP only, with pile IDs and schedule.
2. Review drawings and cage lengths; calculate required sensor cable length (≥ cage length + 0.5 m). Evidence: takeoff sheet and material list signed by supervisor.
3. Verify data loggers and thermal cables have current calibration certificates (≤ 12 months). Acceptance: certificates match serial numbers. Evidence: photos/PDFs stored with pile ID.
4. Prepare tools: multimeter, calibrated thermometer (±0.5 °C), cable ties, heat-shrink, protective sleeves, labels, tablet. Evidence: prestart checklist photo.
5. Brief crew on cable handling during cage lifting/placement and tremie operation. Acceptance: roles assigned; hazards identified. Evidence: toolbox talk record with signatures.

TIP Wire Installation

6. Mark four wire positions at 90° around the cage. Acceptance: spacing within ±10°. Evidence: marked cage photos with compass reference.
7. Secure wires to the cage using non-metallic ties every 1.0 m; maintain 10–20 mm stand-off to avoid pinching. Evidence: close-up photos at top, mid, bottom.
8. Protect cable ends and connectors with heat-shrink and sleeves; label each channel (A–D) and pile ID. Evidence: label photos; label list saved.
9. Provide 300 mm slack loop at the top of each wire to accommodate lifting and trimming. Evidence: photo showing loop dimension on ruler.
10. Perform continuity and resistance check end-to-end with a multimeter. Acceptance: within manufacturer resistance ±10%. Evidence: recorded ohms for each channel.

Data Acquisition and Logging

11. Program loggers with synchronized time (UTC), sampling interval 1–2 min, correct pile ID and channel map. Evidence: configuration screenshot stored.
12. Mount logger above cut-off elevation by ≥0.5 m in a splash-proof enclosure; secure cables away from vibrator paths. Evidence: installation photos.
13. Record ambient and delivered concrete temperatures using a calibrated thermometer (±0.5 °C). Evidence: readings in pour log with time stamps.
14. Start logging ≤10 minutes before concrete placement start; record start/stop times, truck IDs, tremie events. Evidence: pour log and logger time alignment check.
15. Continue logging until peak temperature passes and declines ≥20% from peak (typically 24–72 h). Evidence: time–temperature plot demonstrating decay.

Data Analysis and Interpretation

16. Align data to depth; generate temperature vs time and temperature vs depth plots for each channel. Evidence: exported plots (PNG/PDF) per pile.
17. Compute mean temperature by depth across channels; flag segments with any channel deviating >20% from mean over ≥0.5 m. Evidence: variance table.
18. Identify asymmetric gradients suggesting cage offset; criterion: cross-channel difference >3 °C sustained ≥1.0 m. Evidence: annotated plots with notes.
19. Evaluate toe and top responses; investigate low toe peak or delayed rise indicating soft bottom or debris. Acceptance: toe within ±10% of adjacent segment mean. Evidence: toe zoom plot.

Acceptance and Reporting

20. Correlate anomalies with pour events (interruptions, tremie lifts, obstructions). Document any mitigating evidence (video, photos). Evidence: timeline overlay.
21. Issue acceptance when no significant anomalies per criteria and consistent cross-channel behavior. State acceptance per approved project specifications and authority requirements. Evidence: signed acceptance form.
22. Compile report: raw CSV, calibration certificates, plots, photos, logger/pile IDs, and conclusions. Export PDF/Excel with QR link to data archive. Evidence: distributed report receipt list.

Planning TIP for Drilled Shafts and Bored Piles

A successful Thermal Integrity Profiling program begins with clear scoping and instrumentation planning. Confirm that TIP is the selected method and explicitly exclude CSL to avoid mixed procedures. Check pile geometry, reinforcement details, and anticipated concrete heat development so sensor cable lengths, logger channels, and sampling intervals are correctly specified. Calibrate the thermometer (±0.5 °C) and verify logger clocks in UTC to keep pour logs aligned with time–temperature curves. During prestart, assign roles for cable handling, tremie coordination, and data custody. Environmental factors matter: cold groundwater or large diameters can delay peak temperatures and alter gradients, so plan to log for 24–72 hours. Create a data template that ties each channel to its circumferential position (e.g., 0°, 90°, 180°, 270°), enabling later identification of cage offset as asymmetric signatures. Finally, define objective criteria for anomaly flags and acceptance per approved project specifications and authority requirements.

Exclude CSL from the scope to keep the workflow consistent.
Match cable length to cage length plus at least 0.5 m.
Synchronize logger time with pour logs in UTC.
Plan logging duration for peak and decay capture.
Map channels to cage angles for later comparison.

Installation and Logging Best Practices

Install four thermal cables at 90° spacing around the reinforcing cage, tied every 1.0 m using non-metallic fasteners. Provide 300 mm slack at the head and protect connectors with heat-shrink and sleeves. Keep cables clear of vibrators and tremie lines to prevent damage or shorting. Before lowering the cage, perform continuity and resistance checks; values within manufacturer tolerance (±10%) confirm intact circuits. Program data loggers with a 1–2 minute sampling interval and correct channel mapping, and mount the enclosure above cut-off elevation by at least 0.5 m. Start logging no later than 10 minutes before placing concrete and record ambient and delivery temperatures. Continue logging through the temperature peak and early decay (≥20% drop from peak), typically 24–72 hours, to stabilize interpretation and reduce false flags from early thermal transients.

Use non-metallic ties every 1.0 m along the cage.
Maintain 10–20 mm stand-off to avoid pinching.
Start logging within 10 minutes before placement.
Protect logger and cables from splash and vibration.
Record ambient and concrete delivery temperatures.

Interpreting Curves and Making Acceptance Decisions

Interpretation compares each channel’s temperature by depth against the multi-channel mean. Uniform sections display similar peaks and gradients. Potential defects appear as sustained cold zones, delayed rises, or asymmetric gradients at matching depths. Flag segments where any channel deviates more than 20% from the mean over at least 0.5 m, or where cross-channel differences exceed 3 °C for 1.0 m or more. Correlate flagged depths with the pour timeline (tremie lifts, pauses, or obstructions) to distinguish construction effects from true anomalies. Evaluate the toe: unusually low peaks or flat gradients can indicate soft bottoms or debris. Acceptance is issued when the shaft exhibits consistent cross-channel behavior without significant anomalies, supported by plots, logs, and photos, and documented per approved project specifications and authority requirements.

Compare channels against the depth-based mean.
Flag >20% deviation sustained over 0.5 m.
Watch for >3 °C cross-channel differences.
Correlate anomalies with pour timeline events.
Document acceptance with plots and evidence.

How to Use This TIP Checklist

Preparation: Load project, pile IDs, and logger serials. Confirm TIP-only scope, tools, calibrated thermometer, cables, ties, sleeves, and enclosures are available.
Site setup: Verify access, safe lifting plan for cages, and protected area for logger installation above cut-off elevation with power/battery checks.
Activate interactive mode: Tick items as completed, attach photos, and add comments for anomalies, decisions, and calibration evidence.
During works: Use the checklist on a tablet to guide installation, logging, and documentation, ensuring time stamps align with pour logs.
Export: Generate consolidated PDF/Excel with data plots, logs, and photos; embed QR code linking to the source archive for verification.
Sign-off: Capture digital signatures from contractor, tester, and reviewer; distribute and archive per approved project specifications and authority requirements.

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Ines Oliveira Ines Oliveira

Jan 13, 2026

FAQ

Question: How many TIP wires are required and where should they be placed?

Most projects use four thermal cables at 90° spacing to capture uniform circumferential coverage. Position them along the reinforcing cage from toe to above cut-off elevation. Tie every 1.0 m with non-metallic fasteners, keep a 10–20 mm stand-off, and label channels so later analysis can identify asymmetric temperatures that suggest cage offset or local defects.

Question: When should logging start and how long should it continue?

Start logging no later than 10 minutes before the concrete placement begins to capture the initial temperature rise. Maintain a 1–2 minute interval and continue through the peak and early decay. As a guide, log until temperatures fall at least 20% from peak, typically 24–72 hours, depending on pile diameter, mix heat, and site temperature.

Question: What temperature patterns indicate anomalies during TIP analysis?

Suspect anomalies when any channel is more than 20% colder than the depth-based mean over a segment of at least 0.5 m, or when cross-channel differences exceed about 3 °C for 1.0 m. Cold zones may indicate necking or inclusions; asymmetric gradients can indicate cage offset. Correlate flagged depths with pour events before concluding severity.

Question: How does TIP differ from CSL, and why is CSL excluded here?

TIP measures the concrete’s heat of hydration using thermal cables, highlighting cross-sectional uniformity and toe conditions without installing tubes. CSL uses ultrasonic waves between tubes. This checklist excludes CSL to keep procedures single-subject and consistent; use TIP when thermal signatures are advantageous or tubes were not installed. Follow project requirements when selecting methods.

Question: What if a wire fails during placement or shows no data?

First, verify connections and channel mapping, then check continuity with a multimeter. If the wire is open-circuit, proceed with remaining channels and document the failure. Assess whether coverage remains adequate for interpretation; if not, consult the engineer on contingency actions per approved project specifications and authority requirements.