Strain Gauge Location for Week-4 Lab

Question

“It is given that the strain gauge is located approximately at 35.0 [%] of the span of the bridge. I have checked the diagrams provided on bblearn, though I am still uncertain about which measurement this is. My question is: Is it 35 [%] of the linear distance, or, since the bridge has a parabolic like shape, is it 35 [%] of the generally parabolic distance? “

Response

This is an good question that made us realize we hadn’t shown you the strain gauge location on the bridge as we had intended – the result of the rain disruption last Friday.

John Devitis provided the following information that will help you, in conjunction with the drawings, to locate the place they are applied.

The strain gauges are located 85’ east of Pier F on the New Jersey Truss span.  You can ignore the information about the percent location since this is more precise.

Each member of the truss is straight so the overall shape of the bridge doesn’t matter.  For your purposes you can assume the truss member is horizontal (it’s close enough).