Failure body after Horn
We calculate with the sliding wedge and prism model up to the ground surface, with silo effect from 2D and an iterated slip angle – as described in the DAUB recommendation.
Face support pressure calculation for shield and pipe-jacking drives – by the engineers of BabEng
We calculate your support pressure – transparently.
The engineers of BabEng determine the required and the permissible support pressure at the tunnel face according to the DAUB recommendation (2016) and ZTV-ING – with our calculator FaceSupport. You receive a report with ground section, sliding wedge and all verifications.
Request a calculation Learn more
Enquiries to contact@babeng.com. Employees of BabEng and Tunnelsoft open the calculator via “Launch”.
What you get from us
All operating modes
Normal advance as well as one-third, half and full lowering for personnel entry, each with local ordinate checks and control tolerance.
Blow-out and uplift
We check the maximum permissible support pressure against the required one. If cover is insufficient, we propose ballast loading.
Internal stability
For slurry drives: required yield strength of the support slurry from micro-stability and pressure gradient.
Ground you can see
Layers, groundwater, surcharges and the geology at the face in a true-to-scale section – not just tables.
Report as PDF
Results, input data, graphics and calculation basis in one report with project, client and author details.
Traceably documented
Every calculation is stored per project with version, author and time – changes stay traceable.
Direct contact
The engineers who carried out the work answer questions on assumptions, results and report.
Result at a glance
For each operating mode we state the minimum and maximum support pressure and a recommendation – rounded to the machine's setting precision (0.1 bar), on the safe side.
| Operating mode | pmin [bar] | pmax [bar] | recommended [bar] |
|---|---|---|---|
| Normal advance | 1.5 | 2.6 | 1.7 |
| One-third lowering | 1.7 | 2.6 | 1.9 |
| Half lowering | 1.8 | 2.6 | 2.0 |
| Full lowering | 1.9 | 2.6 | 2.1 |
Example: DN 6000, slurry, 15 m cover, sand and gravel, groundwater 4 m below surface, traffic load 33 kN/m².
The process
- 1
Enquiry
You send us the project, the ground investigation report and the machine data (diameter, cover, groundwater, surcharges).
- 2
Calculation
Our engineers model the ground in the calculator, calculate all operating modes and assess the results.
- 3
Report
You receive the report as PDF with support pressures, verifications and graphics – including the assumptions to be confirmed by your geotechnical engineer.
Basics
- DAUB: Recommendations for Face Support Pressure Calculations for Shield Tunnelling in Soft Ground (2016)
- ZTV-ING, Part 7, Section 3: Mechanised shield tunnelling methods
- DIN 4126 (stability of diaphragm walls) for the internal stability of the slurry
- Failure body model after Horn (1961), silo theory after Janssen (1895)
The assumptions made must be confirmed by the client's geotechnical engineer. FaceSupport does not replace a checked structural analysis.
Request a calculation
Write to us at contact@babeng.com. The calculation is carried out by the engineers of BabEng using the FaceSupport calculator.
Employees of BabEng and Tunnelsoft open the calculator via “Launch” at the top right (sign-in with the Microsoft account).