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Full workflow — realistic case

This page walks through a realistic project: rock slope with water, seismic, tension crack and a reinforcement scheme of passive nails plus drape mesh.

Step 0 — Project details

Open the Project details card at the top of the screen:

  • Description: short identifier of the case
  • Site: location
  • Lat / Lon / Alt: useful for the report header
  • Date: today
  • Code: choose between Characteristic values (γ = 1.0), NTC 2018 (A2+M2+R2), or one of the EC7 design approaches DA1/DA2/DA3

The applied γ factors chip strip immediately below shows the partial factors that are currently in use.

Step 1 — Geometry of the wedge

Enter the geometry of the rock block under analysis:

Parameter Meaning
H slope height [m]
β slope face dip [°]
α failure plane dip [°]
ψ upper face dip [°] (0 = horizontal bench)
B block depth (length ⟂ to the section) [m]

If a tension crack is present, enable it and fill in:

Parameter Meaning
T crack distance from the crest [m]
θ crack dip [°]

The 2D section on the right updates in real time. The α crit button next to α automatically searches for the most unfavourable α (sweep over the kinematically admissible range).

Detail →

Step 2 — Material on the failure plane

Two strength criteria are available:

  • Mohr-Coulomb (linear): τ = c + σn·tan φ
  • Barton-Bandis (non-linear): τ = σn·tan(φb + JRC·log₁₀(JCS/σn))

Use Barton-Bandis for rough rock joints at low normal stress, where the roughness dilation i_eff is significant.

Detail →

Step 3 — Actions

Water

  • Hw: water level ponded at the toe (lake, valley aquifer)
  • Zw: water depth in the discontinuity (generates uplift U on the plane)
  • Pressure distribution: triangular (max at mid-height / at toe / at crack base) or uniform
  • Permeable slope toggle: connects external water to the discontinuity at the same level

Seismic

  • αs = kh: horizontal pseudo-static coefficient (NTC Tab. 7.11.I)
  • Ω: seismic direction [°]

External load

  • E: magnitude per metre [kN/m]
  • δ: inclination [°] (δ=0° horizontal toward the valley = unfavourable, δ=90° vertical = weight, δ=−90° upward = anchor pull)
  • Type: permanent (γG) or variable (γQ)

Detail water → · Detail seismic → · Detail external →

Step 4 — Reinforcement

Catalogue

Build a catalogue of nail/anchor types and mesh types. Each type carries either:

  • a manually assigned capacity F [kN], or
  • a computed design resistance Rd from the NTC formulas (§6.6 for anchors, §6.7 for nails)

Install reinforcement

Use + add reinforcement to add rows of nails/anchors at given Yt heights on the slope face, with horizontal spacing and inclination Δ. For meshes, simply pick the mesh type from the catalogue.

Auto-design

The auto-design button computes the number of rows, positions and spacing needed to meet a target FS. Optional with AI review adds a technical comment, constructability concerns and refinement suggestions.

Detail nails → · Detail anchors → · Detail meshes →

Step 5 — Read the result

  • The factor of safety FS is shown in the lower-left analysis panel
  • The overturning Fr ratio is the structural overall check around the toe
  • The Computed geometry card shows L, M, Q, A, W
  • The Forces on the plane card shows N, S, τ, U, V
  • The Design resistances card (visible when NTC calculation is enabled) shows the per-nail breakdown and NTC-style checks

Step 6 — Verification under the chosen code

Detail verification →

Step 7 — Export

Menu Export: Word report, SVG/PNG drawing, DXF technical drawing, or open the section directly in Trispace NX (web 2D CAD editor of the suite).

Detail export →