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Meshes — R1 drape and R2 cable panel

Two mesh families are supported.

R1 — Drape rock-fall mesh (adhering)

Wire mesh held against the slope face by a regular grid of short nails. The mesh exerts an equivalent uniform normal pressure q on the wedge.

Capacity

\[q = \frac{T_{nail}}{\text{spacing}_O \cdot \text{spacing}_V}\]

where Tnail is the single nail capacity and spacing_O × spacing_V is the nail grid (typical 3×3 m).

Input fields

Field Notes
Wire φ [mm] wire mesh diameter (typical 3 mm)
Mesh H/V [mm] wire mesh opening (typical 80×80 mm)
Spacing H/V [m] nail grid (typical 3×3 m)
T nail [kN] single nail capacity (declared by the supplier)

The card shows the computed q in kN/m². Toggle off "Compute q from parameters" to enter q manually.

Where it enters the analysis

R1 contributes a normal force on the slope face. The components R1x, R1y are added to the global Fx, Fy together with the other actions.

Short fixing nails vs structural nails

A common question: should the nails fixing the R1 mesh also be modelled as separate passive nails in the Reinforcement section?

  • Case A — short fixing nails (do not cross the failure plane): they only hold the mesh. Already represented by T_nail / mesh_area = q. Do NOT add them as separate reinforcement.
  • Case B — long structural nails (cross the failure plane, anchor in intact rock): they contribute directly to wedge stability (force K + Clouterre shear). Model both the R1 mesh and the long nails.

Rule of thumb: if the nail length is ≥ 1.5× the depth of the failure plane, it is structural (Case B).

R2 — Cable panel (high-resistance caging)

A grid of high-strength steel cables, mobilising a shear capacity τ per metre of section that adds directly to the resisting shear on the failure plane.

Capacity

\[\tau = T_{cable} \cdot n \cdot \frac{1000}{\text{spacing}_{mm}}\]

where Tcable is the single cable capacity, n is the number of parallel cables and spacing is the cable spacing in millimetres.

Input fields

Field Notes
Spacing [mm] cable spacing (typical 600 mm)
n cables number of cables (typical 1)
T cable [kN] single cable capacity (typical 60 kN for φ8)

Where it enters the analysis

R2 adds directly to the resisting τ on the failure plane:

\[\tau_{total} = c \cdot L + N \cdot \tan\varphi + K_{passive} + \tau_{R2}\]

What RockPlane does NOT verify

  • Punching of the single mesh-nail node (Rpunz) — typically certified by the supplier
  • Global tension of the mesh panel (Rtr,mesh) — same

These are internal structural checks of the mesh product, not stability checks of the wedge. RockPlane uses the declared capacity and inserts it as an action / resistance in the planar stability analysis.