TBM Telemetry — Geotechnical Contingency Sizing
Geotechnical Contingency Sizing for tunnel project performance management.
Tunnel cost overruns correlate with ground-investigation spend more than any other variable — the industry's rule that every dollar of GI saves ten of claims is conservative. This contingency heuristic prices what the boreholes DIDN'T find; denser investigation legitimately shrinks it.
Formula
Note: Planning-level tunnelling estimate — actual TBM performance is set by detailed geotechnical baseline data, machine design and the contractor's means & methods. Use for feasibility framing only.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Geotechnical Contingency Sizing for tunnel project performance management. A free tbm performance & tunnelling tool — no sign-up, no upload, instant results in your browser.
About TBM Telemetry — Geotechnical Contingency Sizing
TBM Telemetry — Geotechnical Contingency Sizing computes the governing relationship contingency = base × (GI factor + fault share×0.5 + urban factor) live as you type. Tunnel cost overruns correlate with ground-investigation spend more than any other variable — the industry's rule that every dollar of GI saves ten of claims is conservative. This contingency heuristic prices what the boreholes DIDN'T find; denser investigation legitimately shrinks it. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use TBM Telemetry — Geotechnical Contingency Sizing
- 1Enter your values — Base drive cost, Ground investigation quality (1 sparse – 3 dense), Known fault/mixed-face share, Urban/sensitive surface? (1/0) (sensible defaults are pre-filled).
- 2Read the live results: Suggested contingency.
- 3Check the "with your numbers" line to see contingency = base × (GI factor + fault share×0.5 + urban factor) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use TBM Telemetry — Geotechnical Contingency Sizing?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula contingency = base × (GI factor + fault share×0.5 + urban factor) with authoritative sources cited on the page (Maidl et al., Mechanised Shield Tunnelling, 2nd ed.; ITA/BTS — Mechanised tunnelling guidelines; NTNU prediction model — hard-rock TBM performance)
- ✓Tunnel cost overruns correlate with ground-investigation spend more than any other variable — the industry's rule that every dollar of GI saves ten of claims is conservative.
- ✓Niche-specific defaults give a meaningful worked answer the moment the page loads
Frequently asked questions
What formula does the tbm telemetry — geotechnical contingency sizing use?+
It evaluates contingency = base × (GI factor + fault share×0.5 + urban factor), exactly as published. Sources: Maidl et al., Mechanised Shield Tunnelling, 2nd ed.; ITA/BTS — Mechanised tunnelling guidelines; NTNU prediction model — hard-rock TBM performance. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
Tunnel cost overruns correlate with ground-investigation spend more than any other variable — the industry's rule that every dollar of GI saves ten of claims is conservative. Planning-level tunnelling estimate — actual TBM performance is set by detailed geotechnical baseline data, machine design and the contractor's means & methods. Use for feasibility framing only.
When is this calculator the right tool for the job?+
Geotechnical Contingency Sizing for tunnel project performance management. A free tbm performance & tunnelling tool. This contingency heuristic prices what the boreholes DIDN'T find; denser investigation legitimately shrinks it. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Do I need to install anything or create an account?+
No. The tool is pure client-side JavaScript: open the page and it works, offline once loaded, with no account, no quota and no data leaving your device.
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