Circular Cover Slab Designer

Slab and support

Outer radius mm Thickness mm Clear manhole Ø mm Bearing width mm

Materials

Concrete fck MPa Steel fyk MPa Nominal cover mm Design bar Ø mm Main bar spacing mm

Radial shear links

Link diameter mm Legs per position Radial spacing mm Tangential spacing mm Zone inner radius mm Zone outer radius mm Strut cot θ

Drawing dimensions

These reproduce the dimensions arrowed on the supplied West Cover plan. Changes update the parametric geometry.

Openings

Select an opening in the plan or schedule. Edit its exact position and dimensions below.

Select an opening to edit.

Loading

Soil depth m Soil unit weight kN/m³ Surcharge kN/m² Additional Gk kN/m² Concrete unit weight kN/m³ γG γQ

Radial FE mesh

Radial rings Sectors Hole sampling Result smoothing

Mesh method

Concentric radial rings with triangular plate elements. Elements intersecting openings are removed. Increase rings and sectors for convergence.

Benchmark not yet run.

ACTIVE CASE

West Cover Slab

ULS 1.35G + 1.50Q

Reviewed baseline

16 link cases

275 mm C32/40 slab · H16 @ 200 top and bottom, each direction · single-leg H10 positions @ 150 radial / 150 tangential from r = 600–1600 mm.

A 260 mm numerical lower bound was not adopted because its refined-mesh flexural utilisation was 0.99. Inputs remain editable; rerun after changes.

Suggested reinforcement

Preliminary

Quick hand checks

EC2

Dimension check

Engineering review

Preliminary engineering tool

Results require mesh convergence and independent verification in validated structural-analysis software. Local opening detailing, bearing, lifting, anchorage and temporary conditions remain designer checks.