Masonry · Lateral load & panels
Masonry panel in two-way bending calculator
Unreinforced masonry panel supported on four sides, or three sides with the top free, under uniform face pressure. Vertical bending capacity Mcv (flexural tensile strength plus precompression) and horizontal bending capacity Mch (perpend factor kp) are converted to an equivalent isotropic panel by affinity, and the collapse pressure follows from the yield-line solution for a simply supported rectangle. Compared with the one-way vertical capacity.
Standard: AS 3700-2018 Cl 7.4.2 (Mcv) and Cl 7.4.3 (Mch, perpend joint factor kp) · yield-line capacity of an orthotropic panel by affinity (Johansen), top-free edge by the symmetry method
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Panel length (between vertical supports) | 6 | m |
| Panel height | 3 | m |
| Leaf thickness | 110 | mm |
| Supports | All four edges | |
| Flexural tensile strength f′mt | 0.2 | MPa |
| Design compressive stress on the bed joint | 0.03 | MPa |
| Perpend factor kp | 1 | |
| Design wind pressure w* | 0.75 | kPa |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Mcv (vertical bending) | 0.303 | kNm/m |
| Mch (horizontal bending) | 1.245 | kNm/m |
| Affine length L·√(Mcv/Mch) | 2.96 | m |
| Equivalent height | 3.00 | m |
| Two-way collapse pressure | 0.82 | kPa |
| One-way vertical capacity 8Mcv/H² | 0.27 | kPa |
- ✓ w* ≤ two-way capacity — 92 %
- ✓ Panel aspect within yield-line validity (L/H ≤ 4)
Method, formulas and assumptions
- Mcv = (φf′mt + fd)Zd with fd ≤ 0.36 MPa; Mch = 2φkp√f′mt(1 + fd/f′mt)Zd ≤ 4φkp√f′mt·Zd; φ = 0.6, Zd = t²/6 per unit length.
- Affinity: the orthotropic panel equals an isotropic one with m = Mcv and length L√(Mcv/Mch); simply supported rectangle collapse load w = 24m/[b²(√(3 + (b/a)²) − b/a)²], b the shorter side.
- Top free edge: treated as half of a panel 2H high (symmetry). AS 3700 Cl 7.4.4 virtual-work coefficients can give slightly different values; openings and return walls change the pattern.
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.