CIV E 530 - OPEN-CHANNEL HYDRAULICS
SPRING 2006
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 450-m long has a fall of 0.19 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 570 86 0.032 1.14 1.06
    Upstream side channel 2520 625 0.048 1.25 1.13
    Downstream main channel 655 78 0.035 1.09 1.05
    Downstream side channel 2670 720 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 = 240 cfs, b = 29 ft, z = 0, So = 0.002, n = 0.030.
    b.   Q = 600 cfs, b = 32 ft, z = 1, So = 0.003, n = 0.035.
    c.   Q = 950 cfs, b = 38 ft, z = 2, So = 0.001, n = 0.040.
    d.   Q = 30 m3/s, b = 4 m, z = 1, So = 0.0015, n = 0.033.
    e.   Q = 48 m3/s, b = 6 m, z = 2, So = 0.0025, n = 0.038.

    Report the actual printed output from CHANNEL.