Loads and combinations

The Design loads card holds the combinations of actions on the foundation. Each row is a combination, already combined (ULS or SLS), with its partial factors.

The actions

For each combination you enter, at the founding plane:

Symbol	Unit	Action
q	kN/m²	Design normal pressure (if set, replaces N)
N	kN	Vertical normal force
M_x, M_y	kN·m	Moments about the x and y axes
H_x, H_y	kN	Shears (horizontal actions) along x and y

If you assign q, the foundation is loaded with a uniform pressure; if you assign N (with any moments), the contact pressure is derived from N and the eccentricity.

Sign convention

The compass icon in the card header opens the sign convention diagram of the actions: N vertical downward, H_x and H_y the shears along the axes, M_x and M_y the moments about the x and y axes.

Design approaches

The Approach menu prefills the partial factors according to the standard. Changing approach updates the factors automatically; if you edit them by hand, the combination becomes Custom.

Approach	Typical use	γ_R,v (R)
A1+M1+R1	NTC — Approach 2	1.0
A2+M2+R2	NTC — Approach 1, comb. 2	1.8
A1+M1+R3	NTC — bearing capacity GEO (R3)	2.3
A2+M2+R3	NTC — R3 variant	2.3
DA1-C1 / DA1-C2 / DA2 / DA3	Eurocode 7 — Design Approach	per EC7
Seismic	Seismic combination	2.3
SLS	Serviceability limit state → settlements	1.0
Custom	Free factors	—

ULS for bearing capacity, SLS for settlements

ULS/GEO combinations are used for bearing capacity; SLS (service) combinations for settlements. A complete project has at least one of each type.

Partial factors

Each combination carries the partial factors applied to it:

• on the parameters (M): γ on tan φ′, on c′ and on c_u;
• on the weights (A): γ on the foundation weight and on the overburden weight;
• on the resistances (R): γ_R,v on the vertical bearing capacity and γ_R,o on the horizontal one (sliding).

The design resistance is R_d = q_lim / γ_R,v.

CSV import

You can import the combinations from a CSV file:

• the CSV template button downloads an example file, with the sign convention reported in the header comments;
• the CSV button imports a file (delimiter ; or ,, decimals . or ,), with columns description ; approach ; q ; N ; Mx ; My ; Hx ; Hy.

Approaches allowed in the CSV: A1M1R1 A2M2R2 A1M1R3 A2M2R3 EC_DA1C1 EC_DA1C2 EC_DA2 EC_DA3 SISMA SLE.

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