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Home My WebLink AboutCT 81-06B; POINSETTIA VILLAGE; HYDRAULIC CALCULATIONS; 1984-02-214±: 53-8a/3 5EC222A/. 1: Rural Area, 4-0.6 Steep. grassed areas (2:1) ----- -.......... ---------------- ------ Forested areas ----------- ------ ----------------- ----- ------ ----- 0.2-04 Concrete or sheet asphalt pavement ---------------- ------------- - ----- 0.8-0.9 Asphalt macadam pavement ----------------------------------- - ----- 0.0-0.8 Gravel roadways or shoulders ------------------------------------ -- - -- 0. Bareeerth------------------------------------------------------- ----- 02-0.9 Turf meadows ....... -------------------- ----------------------- ----- 0.1-0.4 Flat residential, with about 30 percent of area impervious ------ -- ---- 0.5-0.7 0.40 Cultivated flelda------------------------------------------------ ---- . Urban Areas ' - - ----- 0.1-0.3 Fiat residential, with about 60 percent of area impervious OAS Moderately steep residential, with about 50 percent of area ---- . Impervious ---------------------------------- ---------------- Moderately steep built up area, with about 70 percent of area - -- 0.66 80 Impervious--------------------------------------------------- --0. Flat commercial, with about 90 percent of area Impervious-----. . 0.80 I For flat slopes or permeable soil, use the lower values. For steep slopes or impermeable soil, use the higher values. See reference 12, pp. 48-49 for more detailed data. Table,2.--Manning. Roughness Coefficients, n' . . .. - . . . Manning it I. Closed conduits: . range' A. Concrete pipe ------------------------------------------ 0.011-0.013 B. Corrugated metal pipe or pipe arch: 1. 23f by 5-in. corrugation (riveted pipe) 5. Plain or fully waled------------------------------0.024 Paved invert (range values for 26 and 60 per- cent of circumference paved): Flow full depth---- ------ ----------------------- 0.021-0.018 Flow 0.8 depth -------- ------------------------ 0.021-0.016 Flow 0.6 depth ------------ ---------------------- o.019-o.o13 2. 3-by I-In, corrugation ----- --------------------------- 0. 027 3. 6. by 2-in, corrugation (laid bolted)------------------0.032 C. Vitrified clay pipe ----------- ---------------------- ----- 0.012-0.014 • D. Cast-iron 71pe, uncoated ---------------------------- ---0.013 E. Steel pipe ------------------------------------------ ----0.009-0.011 F. Brick- ------------------------------------ ---------- -----0. 014-0. 017 G Mim,11thP. concrete: Wood brass, rough ----------- -----------------------0. u15-0. 017 Wood farms, smooth----- --------- ---------------------0.012-0. 014 Steel forms ------------- ---------- ------------- ___ 0.012-0.013 H. Cemented rubble masonry walls: Concrete floor and top ...... ----------- -------------- - -0.017-0.022 Natural floor ---------------------------------------- 0.019-0.025 I. Laminated treated wood ------------------------ ----- 0.015-0.017 .1 Vitrified clay liner plates ----------------- ------- ------- 0.015 fl• Lined open channels:' A Concrete, with surfaces as indicated: I. Formed, no finish ----------- ------------------------ 0.013-0.017 2. Trowel finish ----------------------------------------0.012-0.014 Float finish ------ ------------------------------------ ü. 013-0. 015 Float finish, some gravel on bottom ------....... ---- 0.015-41.017 S. Ounite, good section --------------------------------- 0.016-0.019 6. Ounite, wavy section .... ----------------- ----------- 0. ot&-o oa B. Concrete bottom float-finished, sides as indicated: Dressed stone In mortar -----------------------------0.015-0.017 Random stone in mortar - ---------------- ---------- 0.017-0. 020 Cement rubble masonry --------------- --------------- 0. 020--0. 026 Cement rubble masonry, plastered ----------------- 0.016-0.020 S.Dry rubble (riprap) --------------------------------- 0.020-0. 03o C. Gravel bottom, sides as indicated: Formed concrete ----------------------- ------------- o_017-o. 020 Random stone In mortar ----------------------------- 0.020-0.023 Dry rubble (riprap) -------------- ------------------- D. Brick ----------------------------- ------------------ --0.014-4.017 0.023-0.033 Footnotes to Table 2 appear on p.54. Appendix t -TABLES Table 1. Values of Runoff Coefficients (C) - for Use in the Rational Method Runoff Type of s,.irface coefficient - (C)' It. Lined open thanr.ela-Continued . . . Manflinj Te. E. Asphalt: range Smooth ------------------- ----------- ---------------- - . 0.013 Rough --- --------- ---------------------------------- 0.016 F. WOOd, planed clean -----------------------------------0.011-4. 013 0. Concrete-linee excavated rock: 1. Good section ----------------------------------------- OL 017-0. am 2. Irregular section ----------- -......................... 0.022-0.027 Ill. Unlined open chaanete: A. Earth, uniform section: I. Clean, recently completed ------------- -------------- 0.016-0.018 2. Clean, after weathering -------------------------------0.018-0.020') 3. With short grass, few weeds ---------------------- ---- 0. (122-0. 027 / 4. In gravely, soil, uniform section, clean.: -------------- 0. 022-a M B. Earth, fairly uniform section: No vegetation----------------------------------------0.022-0.025 Grass, some weeds -------------------------------- --- 0.026-0.030 Dense weeds or aquatic plants in deep channels------0.030-0.033 Sides, clean, gravel bottom --------------------------- 0.025-0.030 Sides, dean, cobble bottom ......... ----------------- 0.030-0.040 C. Dragline excavated or dredged: No vegetation ---- ------------------------------------o.028-o.o33 Light brush on banks -------------------- ------------ 0.030-0. 050 D. Rock: I. Based on design section ...... --------------------- ----0.035 2. Based on actual mean section: Smooth and uniform -- ------------- ---------------0.038-0.040 Jagged and irregular --------------- ............. ---0.040-0.045 E. Channels not maintained, weeds and brush uncut: I. Dense weeds, high as flow depth --------- ------------ 0.08-0.12 - 2. Clean bottom, brush on sides-------------------------0.06-0.08 Clean bottom brush on sides, highest stage of Bow_ - 0.07-0.11 Dense brush, high stage.... ----------------- -------- 0.10-0.14 IV. flighway channels and swales with maintained vegetation S (values shown are for velocities of 2 and 6 f.p s.): A. Depth of flow up to 0.7 foot: I. Bermuda grass, Kentucky bluegrass, buffalo grass: . -. Mowed to 2 incheS------------------------- -....... 0.07-0.045 - Length 4 tog inches ------------------ .....--------- 0.09-0.05 2. Good stand, any grass: length about 12 inches ................ ..--------- .0.18-0.09 Length &.iout 24 inches --- ----------- ...... ...... 0.30-0.15 3. Fair stand, any grass: a. Length about 12 inches ............................. 0.14-0.08 so b. Length a'ut 24 inches ....... .----- .---------- ...0.25 -fl. 15 B. Depth of flow (.7-1.5 feet: L. Bermuda grass, Kentucky bluegrass, buffalo grass: Mowed ti 2 inches ------------------- .------- .....0. 02,-0. 035 .tengtb4-to6 inches_ ---------------------------- 0.08-0.04 2. Good stand, any grass: Length about 12 inches -------- .....------- .. ----- 0.12-0.07 Length a iout 24 Inches ------- .....---------- .......0.20-0.10 3. Fair stand, any grass: Length stout 12 inches ............................0.10-0.or, Length at-out '24 inches ---------- ..................0.17-0.09 V. Street and e1prs.yguttva A. Concrete gutter, troweled finish........ --------------- ..0.012. B. Asphalt pavement: I. Smooth textile ......................................0.013 2. Rough texture .................-------- ............... 0.016 C. Concrete gutter with asphalt pav:ment: Smooth. --------------------------------- .----------- 0.013 Rough ------------- .------ .---------- ........ ......0.015 D. Concrete pavement: Float finish ---------------- --- .--------------- ......0.014 Broom finish ... .----------------------- .-------------- .0.016 E. For gutters with small slope, w tale sediment may ac- cumulate, increase all above va ties of n by- ------------ 0. (8)2 VI. Natural stream channels:' A. Minor streams i (surface width at flood stage less than 1(8) ft.): 1. Fairly regular section: Some grass and weeds, little or no brush --- -....... 0.030-0.035 - Dense grcwtb of weeds, depth of flow materially - greater than w&sd height...... -------- ..... ....0.035-0.05 Some weeds, ligli: brush on banks .................0.04-0.05 Some weeds, hea y brush on banks ---------------- 0.03-0.07 Some weeds, .len,t willows on banks --------------- 0.00-0.08 For trees within cirsnutel, with branches submerged at high stage, iiwrease all above values by-------0.01-0.10 - 2. Irregular sections, a itt pools, slight channel meander; - increase values in la-c about ------ .---------------- 0.014,02 3. Mountain streams, no vegetation in channel, banks - usually steep, trees and brush along banks submerged at high stage: Bottom of gravel, cobbles, and few boulders ....... .0.04-0.05 Bottom of cobbles, with large boulders ............0.06-0.07 53. - I . l. Natural stream channels-Continued B. Flood plains (adjacent to natural streams): Manning it Friction LOSSeS it CrJIThQa*14 .Vetai.Pigw, by M. 7. Webster and L. R. Metcalf Corps of Engineers, Department of the Army; published in Journal I.. Pasture, no brush: 0.030-0.036 of the Hydraulics Division ProceedIngs of the American Society of Civil Short grass--- ------------------------------------- High grass--------- -------- ----------.............. 0.035-0.05 Enaeers, Vol. 85, No. UT 9, September 1959, Paper No. 2148. pp. 3547. 4 For important work and where accurate determination of water profiles 2. Cultivated areas: - IS necessary, the designer is urged to consult the following references and to a. No crop .------------------------------------------ -0,03-0.04 select it by comparison of the specific conditions with the channels tested: h. Mature row crops--------------------------------- 0.035-0.045 FlOW In JIQaf$O75 of Wafer and SimU.ai' Caysoi., by F. C. Scobey, U.S. it . c. Mature field crors --------------------------------- brush--------------- 3, flcvy weeds, scattered -- ........ 0.04-0.05 o.0.07 Department of Agriculture, Technical Bulletin No. SF2. February 1939. of Water In Drainage Channels. by C-. E. Raxnsar U.S. Department of Agriculture, Technical Bulletin No. 129, Movitinber lP.9. 4. Light brush and tre'ss' Winter_ -------------- ............................. 0.05-0.06 'Handboot of Channel Deiqis far Soil and WaterCbnsovetioa, prepared by Summer------------------------- -------------------0.06-0.08 the Stillwater Outdoor Hydraulic Laboratory In cooaatoia with the Oklahoma Agricultural Experiment Station,published t Sl C-cm- .. 5. Medium to dense brush:' ...a. Winter------- ................ ----------------------0.07-0.11. ser-ralton Service, U.S. Department of Mricultwe, Pub4. No. SCS-FP-4k b. Summer ------------------------------------------ 8. Dense willows, summer, not bent over by cunenL... 100-110 aere: 0.10-0.16 0.15-0.20 March 1957, rev. June 1954. 6 Fbo i, of Water in C'i14n oafs PrciecL4 bp Vegthitwc Li,11041, by W. 0. Rae and V.7. Palmer; Division of Drainage and Water Control, Research, SoI3 7. Cleared land with tree stumps, per No sprouts ---------------------------------------- . 0.04-0.05 Conservation Service, U.S. Department.of Agriculture, Tech. SUIt. No. 967, With heavy growth of sprouts ------ -............. 0.06-0.08 . February 1949. 8. Heavy stand of timber, a few down trees, little under- 'For calculations of stage or discharge in natural stream channels, it is - . growth: branches 0.10-0.12 recommended that the designer consult the local District Office of the Surface Water Branch of the U.S. Geological Survey, to Flood depth below --------------- -------- Flood depth reaches branches--------------------- flood more than 0. 12-0. 16 obtain data regarding values of it applicable to streams of any specific locality. Where this pro-cedure is not followed, the table may be Major streams (surface width at stage 100 ft.): Roughness coefficient is usually less than for used as a guide. The values of n tabulated have been derived from data reported by C. E. Ramser (see minor streams of similar description on account of less -footnote 4) and from other incomplete data. effectl"e resistance offered by Irregular banks or vege- $ The tentative values of it cited are principally derived from measurements made fairly but tation on banks. Values of it maybe somewhat reduced, Follow recommciJation of note 7 [(possible. The value For larger streams of most regular sections, with no of it on short straight reaches of natural streams. Where slopes calculated from flood elevations along it considerable length of channel involving meanders and bends, are to be used in velocity calculations by the boulders or rush, may be in the range of front...........0.028-0.033 Manning formula, the value of n must be increased to provide for the addi- tional loss of energy caused by bends. The increase may be In the range of Fáotnolea to Table 2 perhaps 3 to 15 percent. 'Estimates are by Bureau of Public Roads unless otherwise noted and are 'The presence of foliage on trees and brush under flood stage will materially increase the value of it. Therefore roughness coefficients for vegetation in for straight alinement. A small increase in value of it may be made for leaf will be larger than for bare branches. For trees in channels or on banks, channel alinement other than straight. - 5 Ranges fur sees. I through Iii are for good to fair construction. For . and for brush on banks where submergence of branches increases with depth of flow, it will increase with rising stage. poor quality construction, use larger values of it. Table 3.-Maximum permissible velocities in erodible iTable 4.-Maximum permissible velocities in channelsi - channels, based on uniform flow In continuously wet, lined with us.iform stands of various grass covers, well aged channels maintained IC . - ..- = . Maximum permissible - Maximum perm.is- velocities for- . sible velocity on- Material - Co-rer Slope range . Water Water . Erosion- Easily . . Clear carrying carrying resistant eroded water fine sand and soils soils slits gravel F.p.e. F.p.s. 2.5 F.p.a. 1.5 Percent f.p.a. f-p.s..- . - , (0-5----------- - --8 ....- Sandy loam (cancoiloidel) ------------------ 2.5 2.0 INS- 10 8 4 3.0 3.5 2.0 2.2 ash ------ -.......... --------------- 2.0 3.5 5.0 3.7 Smooth brome---------------------------- 3 Blue grania --------------------- ------ - --ver Fine sand (noncolloldal)-------------------- -- -1.5 Silt loam (nonL-olioidal) ---- ----------------- -- 2.0 Stiff clay (very colloidal) ------------ ------- Graded, loam to cobbles (noncolloldal) -- -1.7 5.0 3.7 5.0 3.0 5.0 Eentuckylsluegrass----------------------8--US----------8 4 Io- ' 4 Grass ore--------------------------- 4 3 Ordinary fl.rmoans--------------------------- - 2.5 Volcanic - - 2.5 Graded silt to cobbles (colloidal) ........... Alluvial silts (concolloldal) ---------- ------- 5.5 5.0 Bermudagrass---------------------------5-l0-----------7 5 Lespedeza Seneca....................... Fine gravel --------- --------------------------- - 2.5 Alluvial silts (colloidal) --------------------- - - 3.7 3.5 5.0 2.0 3.0 Buflalograsa------------------------------0.-S 7 Weeping iovegrass..................... Yellow bluesLem Coarse gravel (noncolloidal)-------------- - - 4.0 15 4.0 .0 6.5 ------------------------- 3 5 2 5 Kudzu-------------------------------- 0-5' -------- Cobbles and shingles ------------------------ - - 2.0 - - 3.7 5.5 6.5 Alfalfa ---------------------------------- Shales and hard pans -------------------------6.0 - - 5.0 6.0 5.0 --13.0 -- ----- Crabgrass Common 3 2- lespedeza'---------------------kn-.5 Sudangrass'--- As recommended by Special Committee on Irrigation Research, Arias-lean - ---------- 3 .5 -- ------------ ---------- ------- Society of Civil EngIneers, 1926, for channels with straight 8llrlclnent. For sinuous channels multiply allowable velocity by 0.95 for slightly sinuous, by I From !jundtiook of Channel Design for Soil and Water Cwuerveiion. (See - . 0.9 for moderately sinuous channels, and by 0.8 10 highly sinuous channels footnote 5 table 2.) (45, p. 1237). . ''ise velocities over 5 f.p.s. only where good covers and prOper maintenance can be obtained. '.)o not use on slopes steeper than 10 percent. - 'Jse on slopes steeper than 5 percent is not recommended. 'Annuals, used on mild slopes or as temporary protection until permanent covers are established. .. - - - . 4-. - . •• 54 . . . H ,. -•. 8-56 I3A'smrlook OF H'rl)RAULJC", Table 5. Values of K in the Formula ,Q K6)4 for Trape- zoidal Channels Q discharge I) - critfral k'pth S bottom width of channel Side slopes of channel, rn,tin of horieont,,il to vertical bVPr V i *[I .01 .0057 .0057 .0057 .0057 .0057 .0057 .0057 .0057 .0058 .0058 .02 .0100 .0161 .01131 .0102 .0162 .0163 .0104 .0165 .0165 .0167 .03 .0295 .0296 .0297 .0298 .0299 .0302 .0304 .0306 .0309 .031 .08 .0456 .0458 .0401 .0403 .0408 .0473 .0478 .0485 .0493 .04...54 .0634 .0638 .0642 .0646 .0050 .01350 .0668 .0677 .0686 .0704 06 .0838 .0840 .0848 .0853 .0859 .0873 .0887 .0902 .0916 .0041 07 .1050 .1060 .1069 .1079 .1089 .1109 .1130 .1151 . .1173 .1211 .08 .1283 .1296 .1310 .1323 .1337 .1306 .1395 .1426 .1450 .1521 09 .1531 .1549 .1567 .1585 .1604 .1043 .1683 .1724 .17013 .195 .10 .1793 .1816 .1840 .1864 .1889 .1940 .1992 .2046 .2101 :2214 .11 .2089 .2098 .2128 .21.59 .2191 .2250 .2323 .2392 .2463 .2607 .12 .2357 .2394 .2431 .2470 .2509 .2591 .2676 .2762 .2851 .3032 .13 .2658 .2702 .2748 .2796 .2844 .2945 .3049 .3156 .3265 .348 .14 .2971 .31)24 .3079 .3137 .3196 .3318 .3444 .3574 .3706 .3975 .15 .3295 .3358 .3424 .3493 .3503 .3710 .38131 .4015 .4173 .4495 .16 .863 .370 .A5. .378 .386 .395 .412 .430 .448 .467 505 .18 J77 .433 J5 25,435.456,jZ& .497 .519 .563 .4F .481 .19 .470 .454 .493 .465 .506 .476 .519 .499 .546 T5 .574 .549 .603 .574 .632 .625 .691 .20 .507 .520 .534 .549 .5134 .594 .626 .659 .692 .700 .21 .546 .561 .576 .503 .610 .645 .081 .718 .755 .832 .22 .585 .602 .620 .638 .657 .697 .737 .779 .822 .008 .23 .626 .644 .664 .685 .706 .751 .796 .843 .891 .988 .24 .867 .688 .710 .733 .757 .806 .858 .910 .963 1.071 ,2.5 .709 .732 .757 .782 .800 .864 .921 .979 1.038 1.158 .28 .752 .777 .805 .833 .862 .923 .986 1.051 1.116 1.248 .27 .798 .824 .854 .885 .918 .985 1.054 1.125 1.197 1.343 .28 .840 .871 .904 .938 .974 1.048 1.124 1.202 1.281 1.441 .29 .886 .919 .055 .903 1.032 1.113 1.197 1.283 1368 1.543 .30' .932 .909 1.008 1.049 1.002 1.180 1.272 1.36.5 1.458 1.640 .81 .970 1.19 1.062 1.107 1.153 1.240 1.349 1.450 1.552 1.759 .32 1.027 1.070 1.116 1.165 1.2111 1320 1.428 1.537 1.648 1.873 :33 1.075 1.122 1.172 1.225 1.280 1.393 1.510 1.828 1.748 1.991 .34 .35 1.124 1.175 1.229 1.286 1.345 1.468 1.594 1.722 1.851 2.113 1.174 1.229 1.287 1.349 1.413 1.545 1.680 1.818 1.958 2.240 .36 1.225 1.283 1.348 1.413 1.481 1.623 1.769 1.917 2.087 2.370 .37 1.276 1.339 1.407 1.478 1.552 1.704 1.860 2.019 2.180 2.505 .38 1.328 1.305 1.468 1.544 1.623 1186 1.954 2.124 2.296 2.844 .39 1.381 1.453 1.530 1.612 1.697 1.871 2.050 2.232 2.416 2.787 .40 1.435 1.511 1.694 1.681 1.771 1.958 2.149 2.313 2.539 2.935 .41 1.489 1.570 1.658 1.752 1.848 2.046 2.250 2.457 2.865 3.087 .42 1.544 1.630 1.724 1.823 1.9213 2.137 2.353 2.573 2.79.5 3,243 .43 1.599 1.891 1.791 1.896 2005. 2.229 2.460 2.693 2.929 3.404 .44 1.655 1.752 1.859 1.970 2.080 2.324 2.568 2.816 3.066 3.570 .45 1.712 1.815 11.928 2.0413 2.168 2.421 2.679 2.942 3.206 3.740 OPEN CHANNEL8 WITH NONUNIFORM FLOW 8-57 .. . . Table -5. Values of K• in the Formula Q Kb-54 for Trape- zoidal Channels (Concluded) - discharge D - critical depth S - bottom width of channel .. D. Side Rinpee of shannl, ratio of horisontel to vertical -1 -1 -1 1-1 I4-1 2-123-1 3.-I 4-I 1.997 2.123 2.268 2.520 8.070 3.85 3.91 .46 1.769 1.878 2.793 .47 1.827 1.942 2.068 2.201 2:338 2.620 2.909 3.202 3.50 4.0 .48 1.886 2.007 2.141 2.281 2.425 2.723 3.028 3.337 3.05 4.2 .40 1.945 2.073 2.214 2.362 2.514 2.828 3.150 3.476 3.80 4.4 .50 2.005 2.140 2.288 2.444 2.605 2.936 3.274 3.617 3.96 4.6 .51 2.065 2.207 2.383 2.527 2.697 8.045 8:401 3.76 4.13 4.8 .52 2.127 2.276 2.440 2.612 2.700 3.138 3.530 3.91 4.29 5.0 .53 2.188 2.345 2.517 2.698 2.885 3.270 3.663 4.06 4.48 5.2 .54 2.250 2.415 2.595 2.786 2.982 3.385 3.798 4.21 4.63 8.4 .55 2.313 2.485 2.675 2.874 3.080 3.503 3.935 4.37 4.81 5.7 .58 2.377 2.557 2.755 2.965 3.180 3.62 4.08 4.53 4.09 5.1 .57 2.441 2629 2.837 3.056 3.282 3.75 4.22 4.70 5.18 6.1 .58 2.505 2.702 2.920 3.149 3.385 3.87 4.36 4.88 5.37 8.3 .50 2.370 2.776 3.004 3.243 3.490 4.00 4.51 5.03 5.56 6.6 .60 2.636 2.851 3.088 3.339 3.508 4.13 4.68 5.21 5.76 8.1 .61 2,702 2.928 8.174 3.44 8.70 4.28 4.82 5.39 5.98 7.1 .62 2.769 3.002 3.261 3.53 3.81 4.39 4.98 5.57 6.16 7.3 .63 2.836 3.079 3.349 3.63 3.93 4.52 5.14 5.75 8.37 . 7.6 .64 2.904 3.157 3.438 3.73 4.04 4.66 5.30 5.94 8.59 7.f .65 2.972 3.236 3.529 3.84 4.15 4.80 5.48 6.13 8.80 8.1 .66 3.041 3.315 3.62 3.94 4.27 4.04 5.63 8.33 7.02 83 .67 3.110 3.396 8.71 4.05 4.39 8.09 5.80 8.52 7.25 8.7 .88 3.180 3.477 3.81 4.15 4.51 5,24 5.98 6.73 7.48 . 8.1 .89 3,250 3.558 3.90, 4.26 4.03 5.39 8.15 8.93 7.71 .70 3.321 3.841 4.00 4.37 4.75. 5.54 8.33 7.14 7.95 9.5 .1 3.39 3.72 4.09 4.48 4.88 5.69 8.52. 7.38 .8.19 . 9 .72 3.46 3,81 4.19 4.59 .5.00 5.85 8.70 7.57 8.44 73 354 . 3.89 4.29 4.70 5.13 8.01 6.89 7.79 8.69 10. '.74 3.61. 3.98 4.39 4.82 5.28 6.17 7.08 8.01 8.94 10.81 .75 3.68 4.06 4.49 4.94 5.39 6.33 7.28 8.24 9.20 11, .76 3.78 4.15 4.50 5.05 5.53 6.51) 7.48 8.47 9:47 .11 .77 3.83 4.24 4.69 5.17 8.66, 6.138 7.68 8.70. 9.73. IL .78 3.01 4.33 4.80 5.29 5.81)' 6.83 7,88 8.04 10.01 12. .79 3,98 4.42 4.90 5.41 5.94 7.01 8.09 9.18 10.28 12.49 .80 4.06 4.51 5.01 5.54 8.08 7.18 8.30 0.43 10,56 12.84 .82 4.21 4.69 5.23 6.79 8.36 7.54 8.73 9.93 11.14 13.56 .84 4.37 4.88 5.45 6.04 6.66 7.91 9.17 10.45 11.73 14.3 .86 4.52 5.01 5.67 6.31 8.96 8.28 9.63 10.98 12.34 15.07 .88 4.68 5.26 5.90 8.57. 7.28 8.67 10.10 11.53 12.97 15.87 .90 4,84 545 6.13 6,85 7.58 9.07 10.58 12.10 13.62 16.68 .92 5.00 5.65 8.37 7.18 7.90 0.48 11.07 12.68 14,20 17.5 .94 5.17 5.85 6.61 7.41 8.23 9.80 11.58 13.27 14.97 18.3 .96 5.33 6.05 6.88 7.70 8.57 10.32 12.10 13.89 15.88 19.2 .98 5.50 6.26 7.11 8.00 8.91 10.113 12.63 14.51 18.40 20.1 1.00 5,87 6.47 7.37 8.30 9.26 11.21 13.18 15.16 17.15 21,! 5-42 HANDBOOK OF HYDRAULICS WEIRS 5-43 Table 5-7. Values of C in the Formula Q = CLHS4, Being the Table 5-9. * Values of C in the Formula Q = CLH% for Weirs of : Mean and Extension of Experimental Results on Weirs of Trapezàitlal Cross Section with Both Faces Inclined Triangular Cross Section with Vertical Upstream Face This table indicates that values of C increase slightly for beads above 1.5 ft and Sloping Downstream Face - This. table should be used only for heads above 0.7 ft. Slope of Value Slope of Value Slope of Value downstream of downstream of downstream of face C face C face C for. Vert. for. Vert. for. Vert. itol 3.85 Otol 3.07 12to1 2.88 2to1 .3.54 7to1 3.02 14to1 2.80 3to1 3.36 Stol 2.08 16to1 2.76 4to1 3.21 Otol 2.94 18to1 2.72 5to1 3.13 lOtol 2.92 20to1 2.69 Slope of up- stream face Slope of down- stream face Width in feet of crest head in feet, H 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1. 1.5 o o I to 2 1 to 1 0.66 2.70 2.82 2.8013.02 3.13 3.243.34 3.44 3.52 3.66 3.82 1 to 2 2 to 1 0.66 2.71 2.79 2.83 2.92 3.03 3.14 3.27 3.32 3.38 3.50 3.61 1 to2 3to1 0.68 2.70 2.76 2.80 2.913.00 3.07 3.143.21 3. 27 X. 37 3. 45 1 to 2 4 to 1 0.66 2.71 2.74 2.84 2.88 2.98 3.06 3.12 3.17 3.21 3.28 3.35 1 to 2 5 to 1 0.68 2.712.80 2.86 2.98 2.03 3.02 3.08 3.12 3.17 3.23 3.26 ito 2 2 to 1 1.32 .... 2.71 2.77 2.80 2.80 2.84 2.88 2.93 2.98 3.08 3.22 1 to 2 4 to 1 1.32 .... 2.76 2.80 2.82 2.82 2.85 2.88 2.91 2.94 3.013. 10 1 to 2 6 to 1 . .....2.79 2.80 2.82 2.85 2.87 2.90 2.93 2.98 3. 08 2to1 2to1 1.32..... 0.67 2.732.861 2 .822.943.943.133.203.263.323.383.433513.61 1 to 1 2 to 1 0.67 - 2.92 3.02 3-12 1 to 2to1 0.87 ' 21 2.502.622.752.872.993.093.l83.273343.463.55 3.153~3.65 3.39 Vertical 2 to 1 0.67 2.55 2.58 2.66 2.77 2.90 2.99 3.09 3 18 3.26 3.51 Table 5-8. Values of C in the Formula Q = CLHt for Weirs of Triangular Cross Section with Both Faces Inclined- For heads above 1.5 ft use the value of C.given for a head of 1.5 ft. Slope of Slope of Head in feet. H up- 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 '1.5 stream face stream face itol itol .... 4.26 4.20 4.14 4.114.11 4.114.10 4.08 3.93 3.75 itol 2to1 3.82 3.80 3.77 3.77 3.79 3.82 3.84 3.85 3.85 3.85 3.84 itol 3tol .3.553.523.483.463.453.463.473.483.473.46 2 t 1 2 to 1 3.88 3.85 3.83.3.81 3.813.83 3.86 3.87 3.87 3.87 3.87 168T '2 to 1 3.8 i 8&82 3.83 3.84 3.84 3.84 3.84 1 t 2 2 to 1 3.74 3.71 3.68 3.69 3.72 3.73 3.73 3.74 3.74 3.73 3.71 Ito 3 2to 1 3653.64 3:64 3.87 3.68 3.69 3.89 3.69 3.60 3.68 3.68 Vertical 2 t 1 8.56 3 47 3.47 3.513.54 3.57 3.58 3.58 3.58 3.59 3.57 * See also Table 5-10. Table 5-10. Values of C in the Formula Q CLH36 forWeirs - of Trapezoidal Cross Section with Both Faces Inclined Slope of upstream face Slope of down- s stream face Width of crest in feet Read In feet, H 1.6I1.8J.o2.5J3.0I3;5J4.0J455.0J5.5 I 3.56 I ill I 2 to 1 2 to 1 0.67 3-573. 56' 3 653 883.70 2 to 1 5 to 1 0.33 3.58 3.56l3.533.48j3.44 3.573.583.6013.62 344 357 3.58 * See also Table 5-9.