AS 3600-2018 default load combinations

This section provides information on the default load combinations (technically, loading combinations) that RAM Concept creates when you start a new AS 3600-2018 file. The purpose and origin of each load combination are given. You can remove or modify any of these load combinations. You can also add load combinations. The load combinations are from AS/NZS 1170.0:2002 incorporating Amendments 1-5, unless noted otherwise.

RAM Concept uses loading types to determine the appropriate factors in some load combinations. For the short-term case the factor ψ will be equal to 1.0 for Live (Unreducible) and Live (Storage) and 0.7 for all other live loadings. For the long-term and combination cases, the factor ψ will be equal to 0.6 for Live (Unreducible) and Live (Storage), 0.4 for Live (Reducible), and 0.0 for Live (Roof). In the case of seismic load combinations ψ will be equal to 0.3 for Live (Reducible) or Parking loads.

Note: Some load combinations in mat (raft) files are of the Lateral Group type and use a "Zero-Tension" analysis. Since a load combination using a "Zero-Tension" analysis does not use Alternate Envelope Factors, then such load combinations in mat files have been expanded into multiple load combinations. In some cases, the assumption that all gravity loads act in the same direction have been used to keep the number of load combinations to a minimum. See Specifying Load Combinations for further description.

All Dead LC

This load combination sums all of the dead loadings, with a load factor of 1.0, that act simultaneously in the standard service condition. This load combination is for information only - it is not used by RAM Concept for design purposes.

Initial Service LC

This load combination is intended for checking requirements upon application of prestress. The load factors used are:

Balance Loading: 1.15 (std & alt) (this includes a 15% increase for long-term losses, which have normally not occurred at this stage)

Note: Although elastic shortening produces a short-term loss, in RAM Concept elastic shortening losses are considered part of the long-term loss lump sum.

Self-Dead Loading: 0.9 (std) & 1.15 (alt)

Temporary Construction Loading (At Stressing): 0.9 (std) & 1.15 (alt)

Service LC: D + ψ L

This load combination is intended for checking the serviceability limit state. The load factors used are:

Balance Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live (Reducible) Loading: 0.7 (std) & 0.0 (alt)

Live (Unreducible) Loading: 1.0 (std) & 0.0 (alt)

Live (Storage) Loading: 1.0 (std) & 0.0 (alt)

Live (Parking) Loading: 0.7 (std) & 0.0 (alt)

Live (Roof) Loading: 0.7 (std) & 0.0 (alt)

Service LC: D + ψ L + S

This load combination is intended for checking the serviceability limit state. The load factors used are:

Balance Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live (Reducible) Loading: 0.4 (std) & 0.0 (alt)

Live (Unreducible) Loading: 0.6 (std) & 0.0 (alt)

Live (Storage) Loading: 0.6 (std) & 0.0 (alt)

Live (Parking) Loading: 0.4 (std) & 0.0 (alt)

Snow Loading: 1.0 (std) & 0.0 (alt)

Max Service LC: D + L

This load combination is intended for checking the serviceability limit state. The load factors used are:

Balance Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live Loading: 1.0 (std) & 0.0 (alt)

Ultimate LC: 1.35D

This load combination is intended for checking the strength limit state. The load factors used are:

Hyperstatic Loading: 1.0 (std & alt)

Dead Loading: 1.35 (std) and 0.9 (alt)

Ultimate LC: 1.2D + 1.5L

This load combination is intended for checking the strength limit state. The load factors used are:

Hyperstatic Loading: 1.0 (std & alt)

Dead Loading: 1.2 (std) and 0.9 (alt)

Live Loading: 1.5 (std) & 0.0 (alt)

Ultimate LC: 1.2D + ψ L + S

This load combination is intended for checking the strength limit state. The load factors used are:

Hyperstatic Loading: 1.0 (std & alt)

Dead Loading: 1.2 (std) & 0.9 (alt)

Live (Reducible) Loading: 0.4 (std) & 0.0 (alt)

Live (Unreducible) Loading: 0.6 (std) & 0.0 (alt)

Live (Storage) Loading: 0.6 (std) & 0.0 (alt)

Live (Parking) Loading: 0.4 (std) & 0.0 (alt)

Snow Loading: 1.0 (std) & 0.0 (alt)

Service Wind LC: D + ψ L + W

This load combination is intended for checking the serviceability limit state with applied wind and live loads. The load factors used are:

Balance Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live (Reducible) Loading: 0.4 (std) & 0.0 (alt)

Live (Unreducible) Loading: 0.6 (std) & 0.0 (alt)

Live (Storage) Loading: 0.6 (std) & 0.0 (alt)

Live (Parking) Loading: 0.4 (std) & 0.0 (alt)

Service Wind Loading: 1.0 (std & alt)

Service Seismic LC: D + ψ L + E

This load combination is intended for checking the serviceability limit state with applied seismic and live loads. The load factors used are:

Balance Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live (Reducible) Loading: 0.4 (std) & 0.0 (alt)

Live (Unreducible) Loading: 0.6 (std) & 0.0 (alt)

Live (Storage) Loading: 0.6 (std) & 0.0 (alt)

Live (Parking) Loading: 0.4 (std) & 0.0 (alt)

Service Seismic Loading: 1.0 (std & alt)

Ultimate Wind LC: 1.2D + ψ L + W

This load combination is intended for checking the strength limit state with applied wind and live loads. The load factors used are:

Hyperstatic Loading: 1.0 (std & alt)

Dead Loading: 1.2 (std) & 0.9 (alt)

Live (Reducible) Loading: 0.4 (std) & 0.0 (alt)

Live (Unreducible) Loading: 0.6 (std) & 0.0 (alt)

Live (Storage) Loading: 0.6 (std) & 0.0 (alt)

Live (Parking) Loading: 0.4 (std) & 0.0 (alt)

Ultimate Wind Loading: 1.0 (std & alt)

Ultimate Seismic LC: D + ψ L + E

This load combination is intended for checking the strength limit state with applied seismic and live loads. The load factors used are:

Hyperstatic Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live (Reducible) Loading: 0.3 (std) & 0.0 (alt)

Live (Unreducible) Loading: 0.6 (std) & 0.0 (alt)

Live (Storage) Loading: 0.6 (std) & 0.0 (alt)

Live (Parking) Loading: 0.3 (std) & 0.0 (alt)

Ultimate Seismic Loading: 1.0 (std & alt)

Sustained Service LC

This load combination is intended for use in load history deflection calculations. The long-term factors from AS/NZS 1170.0:2002 Table 4.1 are used. The load factors used are:

Balance Loading: 1.0 (std & alt)

Dead Loading: 1.0 (std & alt)

Live (Reducible) Loading: 0.4 (std & alt)

Live (Unreducible) Loading: 0.6 (std & alt)

Live (Storage) Loading: 0.6 (std & alt)

Live (Parking) Loading: 0.4 (std & alt)