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Indeterminate Structures and Stress

  1. Nov 3, 2009 #1
    1. The problem statement, all variables and given/known data
    A tunnel of length L = 141 m, height H = 6.9 m high, and width 6.0 m (with a flat roof) is to be constructed at distance d = 60 m beneath the ground. The tunnel roof is to be supported entirely by square steel columns, each with a cross-sectional area of 960 cm2. The mass of 1.0 cm3 of the ground material is 2.8 g

    What is the total weight of the ground material the columns must support?

    I have attached the picture that goes with this problem; hopefully it works!

    2. Relevant equations

    Volume = L(w)(d) = (141m)(6m)(60m) = 50760m^3

    1.0cm^3 = .01m^3

    2.8g = .0028kg

    Total weight = Volume * .0028kg * 9.8m/s^2

    3. The attempt at a solution

    Total weight = Volume * .0028kg * 9.8m/s^2

    I know that this is wrong but I can't come up with anything else that makes sense and could use some help! Thank you in advance!

    Attached Files:

  2. jcsd
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