Description
Tunnel Support & Convergence-Confinement calculation spreadsheet to NATM / Hoek-Brown
This tunnel convergence confinement calculation workbook by 3D-LABS covers ground reaction curve, support characteristic and equilibrium. You enter 18 design inputs and the sheet returns 12 key results with pass/fail checks, every formula visible and traceable to NATM / Hoek-Brown. It is a ready-to-use Excel file for tunnelling engineers, checkers and students who need a clear, auditable calculation rather than a black-box program.
Calculation steps
- Ground Reaction & Support Stiffness & Equilibrium
- Convergence-Confinement Method With Combined Shotcrete And Bolt Support
- In-Situ Stress & Critical Pressure
- Ground Reaction Curve
- Support Stiffness & Capacity
- Equilibrium & Verification
Results you get
- In-situ stress p0 (MPa)
- Strength-to-stress ratio
- Critical pressure (MPa)
- Plastic zone radius (m)
- Maximum convergence (mm)
- Face pre-convergence (mm)
- Shotcrete capacity (MPa)
- Bolt pressure (MPa)
- Combined capacity (MPa)
- Equilibrium pressure (MPa)
- Equilibrium convergence (mm)
- Support check
Codes and references
- Hoek and Brown (2019) — The Hoek-Brown failure criterion and GSI — 2018 edition (2019)
- Carranza-Torres and Fairhurst (2000) — Application of the convergence-confinement method (2000)
- ÖGG Guideline — Geomechanical Design of Underground Structures (NATM) (2010)
- Panet (1995) — Le calcul des tunnels par la méthode convergence-confinement (1995)
- EN 1997-1 — Geotechnical design (support verification) (2004)
What’s included
- Editable Excel workbook (.xlsx) — Tunnel-Support-and-Convergence-NATM.xlsx
- Cover sheet with document number, revision and 3D-LABS title block
- Calculation sheet: colour-coded inputs (blue), formulas (black) and key results (yellow)
- Reference sheet listing the governing standards and editions
- Worked example pre-filled with realistic values
- One-click print to PDF for submission and checking
Frequently asked questions
Can I edit the formulas?
Yes. All cells are unlocked, so you can adapt the tunnel support & convergence-confinement calculation to your own project standards.
Which software do I need?
Microsoft Excel 2016 or later, or any compatible spreadsheet (LibreOffice, Google Sheets).
How do I receive the file?
The download link appears immediately after payment and is also emailed to you.
Is it a substitute for engineering review?
No. The sheet is a design aid — results must be verified by a qualified engineer before use.
What Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator calculates
Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator is an Excel-native engineering calculation tool built by 3D-LABS for engineers, designers, and technical consultants across disciplines. It is used for performing repeatable, verifiable engineering calculations that would otherwise require manual longhand work. Every input is labelled and every output is traceable — the sheet is designed to be checkable, not a black box.
Codes and standards followed
Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator follows industry-standard Engineering codes including ASME, API, AWWA, TEMA, IS, EN, AISC, ACI, and other industry-standard codes. Each formula is cross-referenced to the applicable code clause so your reviewer can trace calculations back to the standard.
If your project requires a different code base (e.g. converting an IS-code sheet to an ASME basis), we can produce a code-variant edition on request. Contact info@3d-labs.com for a variant quote.
What is included in your download
- The Excel calculation file (.xlsx) — fully unlocked formulas, cell-level comments, and a clear input/output layout.
- A sample worked example — realistic inputs plus expected outputs so you can validate the spreadsheet against a known case.
- User notes (PDF) — assumptions, code clauses referenced, and edge-case guidance.
- Revision history — every update to the spreadsheet is logged so you know what changed and when.
- Email support — reply within 24 hours (Monday to Saturday, IST) for questions about the spreadsheet or its use.
Software requirements
Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator runs in Microsoft Excel 2016 or later on Windows and Mac. It is also compatible with LibreOffice Calc and can be imported into Google Sheets (some formatting may shift). No macros are required and no external add-ins are needed — every calculation runs in cell formulas, which means every step is auditable.
Pricing and delivery
Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator is priced at ₹4,999 (approximate USD equivalent shown in the cart). Delivery is instant — after payment you get a download link immediately and a receipt by email. One-time purchase, lifetime access, no subscriptions or hidden fees.
Payment methods: Cashfree (Indian customers) or PayPal International (customers outside India). Volume discounts are available on bundles of 5 or more spreadsheets from the same discipline — contact sales@3d-labs.com for a bundle quote.
Related tools and services
Engineers who work with Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator often also need:
- Other Engineering spreadsheets from our catalogue of 680 tools in this discipline.
- Our Engineering Design Services — for projects where the calculation is only part of a larger scope and you want the full engineering deliverable produced by 3D-LABS.
- Our online training courses — instructor-led programmes on Engineering topics, including software mastery and code walkthroughs.
- Our engineering e-book library — 115+ technical PDF references covering theory, practice, and code interpretation.
Frequently asked questions
What software do I need to run Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator?
The spreadsheet is delivered as a native Excel (.xlsx) file. It runs in Microsoft Excel 2016 or later on Windows and Mac. It also runs in LibreOffice Calc and Google Sheets (with import), though some formatting may shift. No macros are required — all logic runs in cell formulas so you can audit every step.
Which codes and standards does this spreadsheet follow?
Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator follows ASME, API, AWWA, TEMA, IS, EN, AISC, ACI, and other industry-standard codes. Every formula is cross-referenced to the code clause it implements, so your reviewer can trace the calculation back to the standard. If your project needs a different code, contact us — many spreadsheets are available in code-variant editions.
Are the formulas locked or editable?
All formulas are unlocked and editable. You can adapt inputs, add your own load combinations, integrate the sheet into your own workflow, and audit the logic. We do not password-protect our worksheets — an engineer should always be able to verify what the tool is doing.
What is included in the download?
The download includes: (1) the Excel calculation file with all formulas, (2) a sample worked example showing typical inputs and expected outputs, (3) a short user notes PDF explaining assumptions and code clauses used, and (4) a revision history so you can see how the sheet has been updated over time.
Do you offer support if I have questions?
Yes. Email support with any 3D-LABS spreadsheet purchase — reply within 24 hours (Mon-Sat, IST). We also offer paid tuning if you need the spreadsheet adapted to a specific project (typically USD 50-200 depending on scope). Contact info@3d-labs.com for details.
About 3D-LABS engineering spreadsheets
Tunnel Support & Convergence-Confinement (NATM) — Excel Calculator is one of 680 engineering calculation spreadsheets in the 3D-LABS catalogue — the largest curated collection of code-compliant Excel calculators for practising engineers anywhere. Each sheet is built and reviewed by 3D-LABS engineers who use them daily on real client projects across pressure vessel design, storage tank design, piping stress analysis, structural engineering, heat exchanger design, and FEA services since 2003.
Browse the full SpreadSheet Calculations catalogue or the Engineering calculations sub-category. Volume discounts apply on 5+ spreadsheets from the same discipline.
