Adding a margin of safety when estimating how much load a bridge can bear
Yes, but after a certain point, “total load” will stop being your important metric and you need to think about other things like:
Am I assuming a stable, evenly distributed load? (Or e.g. could an army marching across the bridge in step, or traffic only on one side, cause problems?)
Is “the bridge falls down” the only material way the bridge could fail to hold up the traffic on it? (E.g. maybe you want good guardrails.)
Are there other sources of stress other than load? (E.g. “ground is unstable” or “wind blows really fast”.)
Is the bridge likely to stay built as-designed? (Bridges mostly don’t have people trying to take them apart, but a reasonably common source of reduced automobile performance is catalytic converter theft, since it’s a fairly easily accessible part containing precious metals. There are also nonagentic problems like erosion.)
Yes, but after a certain point, “total load” will stop being your important metric and you need to think about other things like:
Am I assuming a stable, evenly distributed load? (Or e.g. could an army marching across the bridge in step, or traffic only on one side, cause problems?)
Is “the bridge falls down” the only material way the bridge could fail to hold up the traffic on it? (E.g. maybe you want good guardrails.)
Are there other sources of stress other than load? (E.g. “ground is unstable” or “wind blows really fast”.)
Is the bridge likely to stay built as-designed? (Bridges mostly don’t have people trying to take them apart, but a reasonably common source of reduced automobile performance is catalytic converter theft, since it’s a fairly easily accessible part containing precious metals. There are also nonagentic problems like erosion.)