See Figure 220. It is necessary to determine the invert elevation of a large con
ID: 1711466 • Letter: S
Question
See Figure 220. It is necessary to determine the invert elevation of a large concrete culvert with an inside height of 16 ft. A direct reading on the floor elevation cannot be made due to the water flowing through the structure. By setting up on the bank of the channel and having the rodperson lean over from the top of the structure with a 6-foot rod they were able to take a reading on the ceiling of the structure with the rod inverted. Using the readings shown in the figure, what is the elevation of the ceiling of the box? 1. 3687.68 2. 3690.32 3. 3674.32 4. 3677.04Explanation / Answer
Option B is correct.
Elevation of the ceiling box=Bench mark Elevation+6 feet rod elevation+inverted rod reading
=3682.82+4.86+2.64
= 3690.32.