Which load combination represents normal vehicular use of the bridge in its 75-year design life with negligible wind effects?

• A. Strength I
• B. Strength II
• C. Strength III
• D. Strength IV

Answer: (A)

The situation tests understanding of which load combination represents normal vehicular use with negligible wind effects. In bridge design, there is a baseline or normal-use load combination that reflects the typical dead load plus the usual live load from traffic over the structure’s service life, without including wind. This baseline is used because wind is treated as a separate action and, when its effect is negligible, it is not included in the normal-use combination. The other combinations are designed for scenarios where additional actions are significant (such as wind-influenced or more extreme loading conditions) and therefore do not represent the everyday operating conditions. So, the appropriate choice is the baseline combination that captures normal traffic loading without wind, aligned with the bridge’s 75-year design life and its ordinary use.