CONTINUOUS ASSESMENT TEST$-1,$ FIFTH SEMESTER$-2024$

OPEN CHANNEL FLOW & IRRIGATION ENGINEERING

Full Marks: $20,$ Time : One hour.

The figures in the margin indicate full marks for the questions.

$($Answer any two$)$

Q$.1\mathrm{.}6.-1.$ Show that in a rectangular channel, critical depth of flow $y_c=\sqrt[3]{\frac{q^2}{g}}.$ Show that specific energy at critical depth, $E_c=(\frac{2}{3})y_c$

A trapezoidal channel $5\mathrm{.}0$ m wide and having a side siope of $1\mathrm{.}5H$:$1V$ is laid on a slope of $0\mathrm{.}0004.$ The roughness coefficient $n=0\mathrm{.}015.$ Find the normal depth of flow for a discharge of $30\frac{m^3}{sec}$ through the channel $($CO$-2).$

$10$

Q$.$ No$.-2.$ Design an irrigation canal through an alluvial soil carrying a discharge of $40\frac{m^3}{sec}$ by Lacey's Silt Theory. Assume mean dia. of bed material as $0\mathrm{.}32$ mm $,$ side slope $1\mathrm{.}5H$:$1V.$ Provide necessary free board.

Also design the channel by Kennedy's theory considering bed slope as $1/4000.$ Kutter's coefficient as $0\mathrm{.}0025,\frac{B}{y}=5$ and $CVR=1.($CO$-5)$

$10$

Q$.$ No$.-3.$ Derive dynamic equation of gradually varied flow. Also state the assumptions in the theory of gradually varied flow. $[$CO$3].$

$10$

Continuous Assessment Test $-$ I, Date: $12-09$

$5$th Sem Civil Engineering, AEC

Geotechnical Engineering $-1,$ Marks: $20,$ Time: $1hr,0\mathrm{.}28$

The void ratio and specific gravity of a sample of clay are $0\mathrm{.}73$ and $2\mathrm{.}7$

$3+3+4$

respectively. If the voids are $92\%$ saturated. find the bulk density, dry density $($CO$1)$ and the water contont of the soil sample. What would be the water content for complete saturation, the void ratio remaining the same?

$0\mathrm{.}27$

Calculate the $\%$ finer of a soil sample using the data obtained by performing $3+2+1+4$ the dry sieve analysis. The total mass of the dry soil sample used in the test $($COI$)$ was $1000$ gm $.$ The sieve analysis test data are tabulated below:

$\backslash$table$[[$IS sieve size $(mm),4\mathrm{.}75,2,1,0\mathrm{.}6,0\mathrm{.}425,0\mathrm{.}3,0\mathrm{.}212,0\mathrm{.}15,0\mathrm{.}075],[$Mass retained $(gm),170,150,160,150,130,80,60,50,30]]$

Find:

$($d$)$ the percentage of coarse, medium and fine sand fractions present in the soil sample.

Te$)$ the percentage of fines $($silt $+$ elay$)$ fraction present in the soil sample.

W$$ the classification of the soil sample as per the Indian standard $($IS$)$ Corce soil classification.t$.2024$

Transportation Engineering I

Time: $30$ min

Total marks: $20$

Briefly describe the significance of testing the consistency of the road paving bitumen at the following three specific temperature: $25C,60C,135C.$ marks:$6($C$03)$ In a bitumen mix, if the weight of aggregate is $1000$ g and bitumen content is $5\mathrm{.}5\%,$ then what will be the volume of bitumen in the mix. Specific gravity of bitumen is $1\mathrm{.}02.$ marks $2($CO$3)$

If the apparent specific gravity is exactly equal to bulk specific gravity of aggregates. explain that the absorption of bitumen is zero.

marks:$2($C$03)$

What is the thickness of the slot of $50-40$ in thickness gauge and length of $25-20$ in Tength gauge? marks:$2($CO$3)$

How obligatory points control the alignment. marks:$5($CO$1)$

Briefly explain about 'GOLDEN QUADRILATERML' of road development in India. marks:$3($CO$1)$