Survey Practice Problem...help!

[Ness B.]

Survey PE Exam Practice Problem...Can anyone help me try to solve this problem?? Seems so trivial but having a really hard time. No solution provided.

 

[youngmotivatedengineer]

Haven't worked the numbers,  but you would need to determine the invert at the location of the existing pipe. Use pythagorean theory. Once you get that should be basic math, make sure you are accounting for the thickness of the pipes.

 

[Booo]

Survey PE Exam Practice Problem...Can anyone help me try to solve this problem?? Seems so trivial but having a really hard time. No solution provided.

View attachment 13509

Just a quick soln. Pls double check my calcs.

inv elevation of 15" vertically below the 6" = { [ (223.75 - 223.4) / (5 + 20) ] * [5 + 5] } + 223.4 = 223.54'

elevation at top of 15" = 223.54 + (15 / 12) + (2 / 12) = 224.96'

elevation at bottom of 6" = 226.35 - (0.5 / 12) - (6 / 12) - (0.5 / 12) = 225.77'

elevation between to the two pipes = 225.77 - 224.96 = 0.81'

Ans. [A]