TWRI 3-A4.--ERRATA
page 4, add the following before the last paragraph in the "Friction
Loss" section.
If the length of the approach reach , Lw, is greater than
1.25 times the bridge opening, b, a better approximation of the friction
loss will be obtained from,
page 9, left column, third line up: Replace ".. given in a previous section of the report .." to ".. presented by Benson and Dalrymple (1967), .."
page 11, right column, line 6: Move all of the text beginning with "For example, if a certain bridge .." through the definition of kφ, ending with " .. for the influence of angularity," to the end of the first paragraph under "Adjustment factors" in the middle of this page.
page 12, right column, last line: Replace "equation 1" with "equation 7"
page 13, right column: replace lower case Greek phi to upper case Greek phi on line 4 of paragraph 1, and on line 7 of paragraph 2. (See, for example, second paragraph in left column of page 13.)
page 15 left column: replace table of z/b versus kz with:
page 15, left column, line 12 up: Change lower case phi to upper case
phi.
page 15, insert the following prior to "Computations" section:
Approach section located >1.25b from bridge
Field conditions sometimes prohibit measuring an approach section at one
bridge opening width, b, upstream of the bridge. For situations where
the bridge opening width needs to be located greater than 1.25 b
upstream, the friction loss term in the denominator of the discharge
equation 7,
should be changed to
page 23, figure 13B: note next to sketch that these curves are for an angle φ of 20°, and cross-reference the sketch to page 15, left column, line 10 up.
page 23, figure 13D: Add to sketch on right the definition of bd:
page 24, figure 14A: In "Standard conditions" legend, show w/b to have a range, 0.1 to 0.5
page 26, figure 16B: In plot of kj versus j on left, the values of j should be 0, 0.02, 0.04, 0.06, 0.08, 0.10, etc.
page 33, right column: On line 3, add " and α1." after "..velocity of approach."
page 33, right column, item 2: Omit A1 and α1 from the parameters listed to be
computed.
page 43, example problem: Replace the term (19.5 +
36(6560)/10840) in the denominator with (19.5 +
21(6560)/10840 + (36 - 21)(6560/10840)2). This
replacement results in changes in the
values computed in the subsequent calculations. The major changes are:
replace V1 = 3.88 with V1 = 3.95
replace V3 = 6.67 with V3 = 6.79
replace F = 0.58 with F = 0.59
add: Lw/b = 36/21 = 1.71 > 1.25