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Sizer allows for sustained live loads with a load duration KD factor of 0.65, and load factors corresponding to those for storage and equipment, or controlled fluids. The design code references for these loads are:
4.1.3.2 5) gives principal load factor for tanks.
4.1.3.2 6) gives companion load factor for storage and equipment areas.
Table A-3, p A-5 note 4 – Controlled fluids
Table A-3, p A-5 note 5 – Storage and equipment
Table A-4, p A-8 note 5 – Gives 1.0 as companion factor for storage for serviceability design
Table 5.2.4.1, ULS Load combos page 17 Note ‡ - gives principal load for fluids in tanks.
Table 5.2.4.2, page 17 ULS Load combos, page 17, Note ** - gives companion load for storage and equipment.
5.3.2.1 refers to the duration of these loads
Note that Sizer now assumes that the only live loads with a permanent load factor are storage loads and controlled fluids loads; it is not possible to enter a load with a KD factor of 0.65 and the same load factors as live occupancy loads.
Storage and Equipment Ls
The table below gives the ultimate limit states load combinations that include storage loads Ls and the load types D, L, S W, and E. Refer to the comments at the end of this section to extend this for load combinations with Ds or H loads.
1Note that this creates two extra load cases by splitting up D + S and D + L compared to what is required by the design code.
2These combinations will only be created if not on an exterior surface – refer to 8 above..
3D, L or D, S not strictly necessary but created for technical reasons
4Design code refers to storage “occupancies”, indicating that all live loads are increased to 1.0
Refer also to the sections after the controlled fluids table for discussion of other load types.
Controlled Fluids Lf
The table below gives a he primary load combinations that include controlled fluid loads Lf and the existing Sizer Load types D, L, S W, and E, and a comparison between the old and new design codes and programs in this regard. Refer to the comments at the end of this section to extend this for load combinations with Ds or H loads.
1Note that this creates two extra load cases by splitting up D + S and D + L compared to what is required by the design code.
2These combinations will only be created if not on an exterior surface – refer to 8 above..
3D,L, D,S not strictly necessary but created for technical reasons
Ls and L
The program creates separate load combinations for D (+ Ds + H ) + Ls or D( +Ds + H ) + Lf, in addition to the combinations D + ( Ds + H ) + Ls/f + L, when occupancy live loads and sustained loads are on the same member. This is because the load combination with Ls/f but without L could govern over the load combination with Ls/f and L, because of the lower load duration factor KD for permanent loading, 0.65 vs. 1.0.
Note that the combinations with Ls without L are not created for combinations that contain short term W or E loads, as these have a KD factor of 1.15, or for with snow loads S, as both the L and L + Ls/f will have a KD factor of 1.0.
Dead loads Due to Soil
If dead soil loads Ds are part of the combination, replace D by D + Ds in this table without creating combinations for D or Ds separately, except for the combination D only.
Hydrostatic Loads
The load combinations for hydrostatic loads H can be arrived at by adding H to each of these combinations, while also retaining the combinations without H.
Wind and Earthqake Loads
The situation where the user adds both wind and earthquake are added to the member is not included, as it does not yield new combinations. The combinations created are the ones created if wind was removed from the set of loads added to the ones created if earthquake was removed from the equation. For example, for D + Ls + W + E, the combinations are derived from those in D + Ls + E and those in D + Ls + W.
Dead load resisting failure load combinations
All the combinations in the above tables, except those containing E, will be replicated using 0.9 as the counteracting load combination factor This includes the extra combinations created by the addition of H described above. For those combinations that contain Ds, the Ds is dropped in creating the dead load resisting failure combinations.
Patterns
The program patterns loads containing D, L, and sustained live loads Ls or Lf, patterning the Ls/f and L in unison. In addition, the program creates patterns for those load combinations with just D and Ls/f. This is because these combinations have a lower KD factor, 0.65, than the combinations with D + L + Ls/f ( 1.0 ) , therefore may be the critical design combination.
Note that you can turn the patterning for individual loads off if you do not wish storage or controlled fluid loads to be patterned.
The load types referred to here are D=dead W=wind S=snow H=earth,groundwater E=earthquake L=live(use,occupancy) Ls=live(storage,equipment) Lf =live(controlled fluids) ) Ds=dead load due to soil.