A very wide rectangular channel is designed to carry a discharge of 5 m³/s per metre width. The design is based on the Manning's equation with the roughness coefficient obtained from the grain size using Strickler's equation and results in a normal depth of 1.0 m. By mistake, however, the engineer used the grain diameter in mm in the Strickler's equation instead of in metre. What should be the correct normal depth?

A very wide rectangular channel is designed to carry a discharge of 5 m³/s per metre width. The design is based on the Manning's equation with the roughness coefficient obtained from the grain size using Strickler's equation and results in a normal depth of 1.0 m. By mistake, however, the engineer used the grain diameter in mm in the Strickler's equation instead of in metre. What should be the correct normal depth?

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

An unsymmetrical trapezoidal channel with one side inclined from horizontal by 35 degree and the other inclined from vertical by 40degree is to be designed to carry a 2.0 cubic meters per second discharge. Determine the dimensions of the channel for most efficient section if roughness coefficient is 0.030 and average longitudinal slope is 0.05. Draw the cross section of the open channel considering the freeboard height. Use Chezy and Kutter’s C formula.
A trapezoidal channel with 3 meters bottom width, side slope 2H:1V, channel gradient of 0.002, and n = 0.025, carries a discharge of 200 m3 /min. Compute the normal depth and velocity. Given data Wbottom (b)= 3 meters Slope= 2:1 S= 0.002 n= 0.025 Q= 200 m3 /min= 3. 33 m3 /sec Normal depth=? Velocity=? Formula below:
A straight weedy-earth channel has the trapezoidal shape ofFig. , with b= 4 m and θ = 35°. The channel has a constantbottom slope of 0.001. The fl ow rate varies seasonallyfrom 5 up to 10 m3/s. It is desired to place a sharp-edged weiracross the channel so that the water depth 1 km upstreamremains at 2.0 m ± 10 percent throughout the year. Investigatethe possibility of accomplishing this with a full-widthweir; if successful, determine the proper weir height Y. Ifunsuccessful, try other alternatives, such as (a) a full-widthbroad-crested weir or (b) a weir with side contractions or(c) a V-notch weir. Whatever your fi nal design, cite theseasonal variation of normal depths and critical depths forcomparison with the desired year-round depth of 2 m.
The side slope of a trapezoidal open channel are 1 horizontal to 1.75 vertical. The bottom width is 2.5m and length of flow is 3m. The coefficient of roughness n=0.015 and the slope of the channel bed is 0.0004. Calculate the velocity of flow (m/s) using Manning's formula. Round answer to one decimal place.
Calculate the depth d in which the discharge (Q = 1.5 m / sec) will flow through the channel with trapezoid - shaped cross section. Width of the channel bed is (b = 2 m), slope of bed (S = 0.05%), sides slope is (Z = 1.5). The channel is excavated in gravel sends in which the roughness coefficient is (n = 0.0247).
3. A trapezoidal channel has a bed width of 3.0 m and side slope of 1 horizontal: 1 vertical. It carries a flow of 9.0 cms (or m⅔) at a depth of 3.0 m. Find the Froude number of the flow.
An unsymmetrical trapezoidal channel with one side inclined from vertical by 35o and the other inclined from horizontal by 40o is to be designed to carry a 2.5 cubic meters per second discharge. Determine the dimensions of the channel for most efficient section if roughness coefficient is 0.025 and average longitudinal slope is 0.05. Draw the cross section of the open channel considering the freeboard height. Use Chezy and Kutter’s C formula.
Critical depth for rectangular channels A rectangular open channel has a bottom width of 6.0 m and a Manning’s n of 0.02. a. For y? =2.0 m and Q =11 m^3/s, find the normal slope. Is the slope steep, critical, or mild? b. For Q =11 m^3/s, find the slope at which critical depth occurs. c. For y? =2.0 m and y? =2.0 m, find the channel slope and corresponding discharge.
Determine the normal depth (m) in a rectangular channel with flowing discharge of 70 m3/s, roughness of n=0.025, slope of 0.001, with bottom width of 6 meters.
find the length of the water profile for a wide rectangular that has a bed slopeof 7.5 cm/km and carries a discharge of 2.5 m2/s. The channel terminates intosudden fall., assuming a critical depth at the sudden fall is 0.612 m. Take the Chezycoefficient as 35 (metric)
1. A 3.1 – m wide rectangular flume carries water at 5.60 m3/s. The bed slope is 0.00078 and n = 0.010. At a certain section, the depth is 92 cm. a. How far therefrom is the depth 80 cm? b. What is the slope of the egl? c. What is the headloss? 2. A rectangular channel 1.8 m wide conveys water at a depth of 1.2 m. a. What is the velocity of flow if it is laid on a slope of 0.002 and n= 0.012? b. What is the discharge if the channel slopes 0.1° and n = 0.016? Use Kutter’s formula for C. c. What is the velocity of flow if S = 0.000263 and f = 0.02?
A rectangular channel flowingnormally full at a depth 1.40 m has base of width 2 m.The flow rate is 3.6 m3/s. It is to be replaced by anefficient rectangular section with the same material andadhering to the same slope. (a) What is the increase inits capacity? (b) If instead the most efficient trapezoidalsection were used, what would be the increase in theflow rate? (c) What percent increase could have beenexpected if the most efficient of all efficient sectionswere used?