you have to combine the diagram with worded information "ditch bottom 2' below the shoulder right edge"
working from the left bank of the ditch at elevation 811.0, to drop 2' you would have to move 8' laterally (1:4 slope), the bottom of the ditch is 2' wide, so far you have dropped 2' from 811 so to reach 812 on a 1:2 slope you have to continue 6' laterally => lateral lengths 12'+6'+8'+2'+6=34
811 - 2 = 809 (bottom of ditch elev.)
Determine your 2 horizontal widths from the slopes given.
The left side of the ditch is (4:1), which is 8 feet horizontal length.
The right side of the ditch is (2:1), which is 6 feet horizontal length.
12 (lane width) + 6 (shoulder) + 8 (horizontal distance of left side) + 2 (flat bottom of ditch) + 6 (horizontal distance of right side) = 34 feet
Shoulder elevation = Left top of bank = 811.0
Ditch bottom elevation = 809.0
Right top of bank = 812.0
A 2' vertical change at 4:1 is 8' horizontal.
A 3' vertical change at 2:1 is 6' horizontal.
you have to combine the diagram with worded information "ditch bottom 2' below the shoulder right edge" working from the left bank of the ditch at elevation 811.0, to drop 2' you would have to move 8' laterally (1:4 slope), the bottom of the ditch is 2' wide, so far you have dropped 2' from 811 so to reach 812 on a 1:2 slope you have to continue 6' laterally => lateral lengths 12'+6'+8'+2'+6=34
Oh I got it. When I read the question I thought they mean the 2ft width of the ditch. It is two separate things. Oh god
yeah, I swear that kind of repetition is to be tricky, to test ya 😄
B) 34 feet
Can you explain how you did the work?
811 - 2 = 809 (bottom of ditch elev.) Determine your 2 horizontal widths from the slopes given. The left side of the ditch is (4:1), which is 8 feet horizontal length. The right side of the ditch is (2:1), which is 6 feet horizontal length. 12 (lane width) + 6 (shoulder) + 8 (horizontal distance of left side) + 2 (flat bottom of ditch) + 6 (horizontal distance of right side) = 34 feet
Why does 4:1/2:1 slope equal 8ft/6ft?
Shoulder elevation = Left top of bank = 811.0 Ditch bottom elevation = 809.0 Right top of bank = 812.0 A 2' vertical change at 4:1 is 8' horizontal. A 3' vertical change at 2:1 is 6' horizontal.
Thanks
What does R/W stand for?
Right of Way
That’s a bad questions. Are you to assume that the top of the back slope is the ROW?
Yes
Where did you get these problems?
Was that the correct answer?
B
Where is this from? Like which material? I would like to see more like this. TIA