Questions:
- If the tunnel had an average depth
of 35 ft. and a cross-sectional area of 48 ft2., what would be
the force on the plug in the freight tunnel, assuming that the tunnel was
3 ft. deeper.
Answer
- To plug the tunnel, a shaft was drilled to pour
in the concrete. The shear strength of the shaft must be greater than the
force of the water in the tunnel. Using the formula F = sBr2
and the shear strength of concrete being 38 lb./in2., find if a
shaft of 6 ft. will be strong enough to hold back the water for the tunnel
in the above problem.
Answer
- Assume that the force on the plug
will be 97,522 pounds. The engineers want the shaft to have a shear strength
of at least 100,000 pounds. Given this information (as well as the information
from the prior problems), what size diameter of shaft, rounded to the next
whole foot, will be necessary?
Answer
- For which of the following tunnels
would the force on the concrete plug be the strongest? Tunnel #1 has an average
depth of 30 ft. with a cross-sectional area of 50 ft2. The 2nd
tunnel has an average depth of 36 ft. and a cross-sectional area of 45 ft2.
Remember that the weight of water is 62 lbs./ft3.
Answer
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