Limit States

Possible foundation limit states are used in the geotechnical calculations of foundations. These include load capacity of the soil, sliding, rotation (local stability), position of a force resultant (uplift, contact area), lifting, average settlement, and settlement difference.

These can be assigned to the Limit State groups of Ultimate, Serviceability, Accidental or Seismic. Regional requirements determine whether a limit state is ascribed to a given group of limit states.

Limit States belonging to several groups or special combination types are distinguished (such as long and short-term combinations, wind, snow or seismic combinations), it is possible to impose a separate limit for each combination type and each Limit State.

Code Combination for Limit States
Ultimate Serviceability Accidental Seismic

ACI

-

capacity of the soil

rotation

average settlement

settlement difference

-

capacity of the soil

BS 8004:1986

-

capacity of the soil

sliding

rotation

average settlement

settlement difference

- -

CSA

-

capacity of the soil

rotation

average settlement

settlement difference

-

capacity of the soil

DTU 13.12Fascicule 62 Titre V

capacity of the soil

position of a force resultant

sliding

rotation

position of the force resultant

-

lifting

sliding

rotation

ENV 1997-1:1994 (EC 7)

capacity of the soil

(combinations A, B and C)

position of a force resultant

(combinations A, B and C)

average settlement

capacity of the soil

-

EN 1997-1:2004 (Eurocode 7)

capacity of the soil

(for combinations of A 1, A2 type, depending on the design approach)

position of a force resultant

(for combinations of A 1, A2 type depending on the design approach)

average settlement

capacity of the soil

-

PN-81/B-03020

capacity of the soil

position of a force resultant

sliding

rotation

average settlement

- -

SNiP 2.02.01-83

capacity of the soil

sliding

rotation

average settlement

capacity of the soil

-

Design approach for EN 1997-1:2004 (EC 7)

In accordance with point 2.4.7.3.4, Robot allows to choose one of three design approaches. The design approach selection is available in the Geotechnical options / Design approach tab. Additional information about the design approaches can be found in the Appendix B.