# Load Combination Table \[TB]

**Strength I:** AASHTO Strength I limit state combination row — basic load combination for normal vehicular use. Pick the result extraction case(s) that represent this combination.

**Strength II:** AASHTO Strength II limit state — owner-specified permit loads without wind.

**Strength III:** AASHTO Strength III — wind in excess of 55 mph (no live load).

**Strength IV:** AASHTO Strength IV — dead-load-dominated combination for long-span bridges.

**Strength V:** AASHTO Strength V — normal vehicular use plus wind of 55 mph.

**Extreme Event I:** AASHTO Extreme Event I — earthquake load combination.

**Extreme Event II:** AASHTO Extreme Event II — ice, vehicle/vessel collision, and similar combinations.

**Service I:** AASHTO Service I — normal operation; used for deflection and most serviceability checks.

**Service II:** AASHTO Service II — prevent yielding of steel structures.

**Service III:** AASHTO Service III — tension in prestressed concrete superstructures (crack control).

**Service IV:** AASHTO Service IV — tension in prestressed concrete substructures (crack control).

**Fatigue I:** AASHTO Fatigue I — infinite-life fatigue check (finite live-load range).

**Fatigue II:** AASHTO Fatigue II — finite-life fatigue check.

Each row defined here will serve as an input to code check templates and is a way to map the analysis results to code check objects.

This section allows the user to map the previously defined limit states to the load combination table. If the user has defined multiple strength 1 limit states with different factors for substructure and superstructure elements, or if they want to exclude the service 3 limit state for a particular code check component, or if they have defined different factors for the constructibility limit state, they must define separate load combination tables here.

The purpose of this is to specify which results from which stage should be used for the steel I-girder code check and pier code check, and whether the corresponding factors are the same for both. If the answer is the same for both, then there is no need for two separate load combination tables. However, if the answer is no, the user must define two separate rows in this section to differentiate between them.

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