EPS Lightweight Fill · Geofoam Design Checker
Indicative grade, load-reduction, settlement & buoyancy checks · to ASTM D6817 / D7180
Geometry & loads
Geofoam / fill thickness, t
g
m
Load-distribution slab thickness, t
s
m
Pavement / cover thickness, t
p
m
Pavement unit weight, γ
p
kN/m³
Traffic / live surcharge, q
kPa
Soil unit weight (for comparison), γ
s
kN/m³
Geofoam grade
Grade (ASTM D6817)
Groundwater (buoyancy)
Submerged block height, h
sub
m
Required factor of safety, FS
req
–
Additional permanent soil cover over the slab (if any):
m
Settlement (optional)
Reference settlement under conventional soil fill
mm
First-order: settlement scales with the change in subsoil stress Δσ.
1 · Load reduction on the subsoil
Δ
σ
— conventional soil fill
–
Δ
σ
— EPS geofoam fill
–
Reduction in stress reaching the soft subsoil
–
2 · Grade adequacy (bearing on the blocks)
Working stress on blocks,
σ
–
Selected grade — resistance @1% strain
–
Utilisation
Design to the compressive resistance at 1% strain (elastic limit). Do NOT design to the 5% / 10% values.
3 · Buoyancy / flotation
Uplift (submerged)
–
Resisting permanent dead load
–
Factor of safety achieved
4 · Indicative settlement
Conventional fill (input)
–
With geofoam (indicative)
–
S_geofoam ≈ S_conventional × (Δσ_geofoam ÷ Δσ_conventional). First-order only — confirm with site-specific consolidation parameters (Cc, e₀, mᵥ) and ASTM D7180.
Disclaimer.
This tool gives first-order, indicative results for concept design and comparison only. It is not a substitute for a qualified geotechnical engineer or for design to ASTM D6817 / D7180. Verify grade, buoyancy, sliding, the load-distribution slab and site-specific settlement before construction. γ
w
taken as 9.81 kN/m³. © Technopol SA (Pty) Ltd · info@technopol.co.za · technopol.co.za
