What is the Tunnel Support multi-solver?

Tunnel Support is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.

Yes. Every step runs entirely in your browser using real numerics — no install, no account, no cloud cost. Custom or private solver packs are available as a paid service.

Structural & Geotechnical Pack · Multi-Solver

Tunnel Support

Ground load & lining. This multi-solver chains 2 solvers into a single guided workflow — run each step in order and carry the result forward.

Workflow steps

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Beam Deflection

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Beam Deflection & BendingLive

Euler-Bernoulli beam theory

Controls

Presets

Span L (m)

Load P (kN)

Flexural rigidity EI (kN·m²)

Euler-Bernoulli theory relates a beam's deflection and internal moment to its load, span, and flexural rigidity EI. Deflection grows with the cube or fourth power of span, which is why doubling a span is far worse than doubling the load. Educational tool — not a substitute for a stamped structural design.

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Data Inspector

Max deflection1.30 mm

Max moment12.5 kN·m

Span/deflectionL/3840

Governing equation

δ = \frac{P L ^{3}}{48 E I} = \frac{10 \cdot 5 ^{3}}{48 \cdot 20000} = 1.30 mm

Reading this result: At L/3840 this beam clears the usual L/360 serviceability limit, so strength (not deflection) is likely to govern the design.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Soil Bearing

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Soil Bearing Capacity (Terzaghi)Live

foundation design

Allowable bearing pressure

400kPa

Allowable load ≈ 801 kN per metre of footing

Controls

Presets

Cohesion c (kPa)

Friction angle φ (°)

Unit weight γ (kN/m³)

Footing width B (m)

Embedment depth (m)

Factor of safety

Terzaghi's equation predicts the ultimate bearing capacity of a shallow footing as the sum of cohesion, surcharge, and self-weight terms, each with a bearing-capacity factor that grows sharply with the soil friction angle. Dividing by a factor of safety gives the allowable pressure. Educational tool, not a geotechnical design.

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Data Inspector

Nc30.1

Nq18.4

Nγ22.4

Ultimate qult1201 kPa

Governing equation

q_{u} = c N_{c} + γ D_{f} N_{q} + \frac{1}{2} γ B N_{γ} = 10 (30.1) + 27 (18.4) + \frac{1}{2} (18) (2) (22.4) = 1201 kPa

Reading this result: Mixed c-φ soil: all three terms contribute — deeper embedment and a wider footing both push the ultimate capacity higher.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Frequently asked questions

What is the Tunnel Support multi-solver?: Tunnel Support is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.
Is it free to use?: Yes. Every step runs entirely in your browser using real numerics — no install, no account, no cloud cost. Custom or private solver packs are available as a paid service.