CIV E 530 - OPEN-CHANNEL HYDRAULICS
SPRING 2007
HOMEWORK No. 5

  1. Determine the normal discharges in channels having the following cross sections, for y = 1.5 m, n = 0.013, and So = 0.007:

    a.   A rectangular section 6 m wide.
    b.   A triangular section with a bottom angle equal to 60o.
    c.   A trapezoidal section with a bottom width of 10 m and side slope z = 1.5

    Use onlinechannel15.php in onlinechannel.sdsu.edu to verify the results. Report the actual printed output from onlinechannel15.php

  2. A channel reach 475-m long has a fall of 0.18 m in the water surface during a flood. Use a spreadsheet to compute the flood discharge using the following data:

    Subsection A (m2) P (m) n α β
    Upstream main channel 590 82 0.032 1.14 1.06
    Upstream side channel 2620 655 0.048 1.25 1.13
    Downstream main channel 675 70 0.035 1.09 1.05
    Downstream side channel 2780 740 0.045 1.18 1.11

  3. Use CHANNEL in onlinecomp.sdsu.edu to calculate critical and normal depth for the following cases:

    a.   Q = 250 cfs, b = 30 ft, z = 0, So = 0.002, n = 0.030.
    b.   Q = 500 cfs, b = 35 ft, z = 1, So = 0.003, n = 0.035.
    c.   Q = 750 cfs, b = 40 ft, z = 2, So = 0.001, n = 0.040.
    d.   Q = 40 m3/s, b = 5 m, z = 1, So = 0.0015, n = 0.033.
    e.   Q = 50 m3/s, b = 7.5 m, z = 2, So = 0.0025, n = 0.038.

    Report the actual printed output from CHANNEL.