hydraulics and geotechnical engineering 2003-2012 zherrinore..
1)
2)
3)
4)
1)
-the father of modern soil mechanics
5)
-3
terzaghi
having a volume of 1. x 10 M g taken from the field
b)
peck
having a volume of 1.x10 M . it has specific specific gravity of
c)
cassagrande
2.60 and water content of 10%. Values of e
3
d)
atterberg
e)
none of these
e
max
= .63 and
= .44 A.
Compute the dry unit weight.
the densification of soil by removal of air which requires
B.
Compute the void ratio.
mechanical energy is called
C.
Compute the relative density.
a)
densification
b)
compaction
c)
consolidation
is known to have a specific specific gravity of 2.6. in order to
d)
liquefaction
determine the moist density of the soil, a portion of soil
e)
none of these
weighing 224 g is put in a 500 cm . It is filled with with 382
6)
A soil sample has a natural water content of 22.5% and it
3
3
deep groundwater deposits where underground water
cm of water to fill the container.
are available for water supply and irrigation is known as
A.
Compute the porosity of the soil.
a)
water table
B.
Compute the degree of saturation.
b)
water wells
C.
Compute the bulk of sp. gravity.
c)
aquifers
d)
saturated zone
compacted. Volume of wet soil is 0.001 m and has a ass
e)
none of these
of 1.6 kg. If the specific gravity of soil is 2.70.
7)
A dry soil mixed with 17% by mass with water and 3
in fluid flow, if the fluids travels parallel to the adjacent
A.
Compute the dry unit weight of soil.
layers and the paths of individual particles do not cross
B.
Compute the void ratio.
the flow is said to be
C.
Compute the degree of saturation.
a)
laminar
8)
b)
turbulent
compacted . volume of wet wet soil is 1x10
c)
critical
mass of 1.6kg. if the specific gravity of soil is 2.61
d)
dynamic
a)
compute the dry density
e)
none of these
b)
compute the void ratio
c)
compute the degree of saturation
A soil sample has a natural water content of 22.5% and it
3
224 g is put in a 500 cm container. It is filled filled with 382 3
cm of water to fill the container. A.
Determine the moist unit of the soil.
B.
Determine the dry unit of soil.
C.
Determine the void ratio.
9)
A dry soil is mixed with 13.5% by mass with water and -3
3
m and has a
3
the field unit wt of soil sample is 1900kg/m and the unit wt of the soil particle is 2600 kg/m
3
a)
compute the dry unit wt if the water content is 12%
b)
compute the void ratio
c)
compute the degree of saturation
10) you are an earthwork construction control inspector and you are checking the field compaction of a layer of soil.
The total weight of soil when saturated 1526 g and
the laboratory compaction curve gives a maximum dry
weight of the soil after drying is 1053 g. If the sp. gr. of
density of 1.482g/cc and optimum water content of
soil is 2.84
16.9%. specifications call for the compacted density to be
A.
Compute the moisture content
at least 95% of the max laboratory value and within +-2%
B.
Compute the void ratio
of the optimum water content. when you did the sand
C.
Compute the porosity
cone test, the following data are as follows. 3
The field unit wt of the soil sample is 1960 kg/m and the 3
volume of soil excavated from the hole=.001337m
unit wt of the soil particle is 2700 kg/m . If the e max =
weight of soil from the hole when wet=2200 g
0.69 and emin=.44
wt of dry soil=1890g
A.
3
Compute the dry unit wt in KN/M if the
a)
determine the field unit wt of soil
water content is 11%.
b)
what is the insitu water content of soil
B.
Compute the void ratio of the solid sample
c)
determine the relative compaction of the soil
C.
Compute the relative density of the soil sample.
4)
3
min
the moist density of the soil, a portion of soil weighing
3)
3
a)
is known to have a sp. gr. of 2.6. in order to determine determine
2)
A soil sample has a mass of 1830 g taken from the field
The field wt of soil sample is 1900 kg/m and the unit wt 3
of the soil soil particle is 2660 kg/m . A.
11) given the different layer of soil with their respective coefficient of permeability:
3
Compute the dry unit weight if the moisture content is 11.5%.
B.
Compute the void ratio.
C.
Compute the degree of saturation.
3
hydraulics and geotechnical engineering 2003-2012 zherrinore..
a)
what is the equation in determining the equivalent horizontal coefficient of permeability
b) c)
what is the equivalent horizontal coefficient of permeability if each soil layer is 3mm thick
a)
determine the total flow of water
what is the total flow if i=.70?
b)
fins the equivalent value of K for both annular and
d)
inner ring
12) a confined aquifer underlies an unconfined aquifer as
c)
shown in the figure
determine the volume of water which percolate after 30 mins in cm
3
16) the laboratory apparatus shown in the figure maintains a constant head in both the upper and lower reservoirs. the soil sample is a silty sand wih a hydraulic conductivity -3
k=5x10 cm/sec and a moisture content of 18.5%. sp. gr=2.70 a)
compute the equivalent horizontal coefficient of permeability
b)
compute the hydraulic gradient
c)
compute the flow rate from one stream to another per meter width 2
13) a reservoir with a 3400m area is underlain by layers of stratified soils as depicted in the figure
a)
compute the seepage velocity in cm/sec
b)
determine the time required for the plug of colored water to pass through the soil.
c)
compute the discharge of water
17) a confined aquifer has a source of recharge as shown in the figure. the hydraulic conductivity of the aquifer is 40m/day and its porosity is .25. the piezometric head in the two well 1325m apart is 65m and 60m from a a) b)
compute the average coefficient of permeability in
common data. the average thickness of the aquifer is
m/hr
25m. and the average width is 4km
compute the interstitial velocity of water moving through the soil if it has a void ratio of .60 express in cm/.sec
c)
compute the water loss from the reservoir in one yr in cu.m assuming that pore water pressure is zero
14) the soil under a dam has four layers of soil with different coefficients of permeability Layer
Depth
1 2 3 4
4 8 12 3
a)
compute
the
average
a)
3
m /day
Coefficient of permeability 5 cm/hr 3 2 1 vertical
coefficient
compute the seepage velocity
c)
compute the time of travel from the head of the
18) a dense silt layer has the f ollowing properties: voidratio=.30 of
compute the transmissibility of the soil when the 2
water table is at the ground surface in m /day c)
b)
aquifer to a point 4km downstream in days
permeability in meters/day b)
effective diametr D10=10μm capillary constant=.20cm
2
a)
find the height of the capillary rise in the silt
b)
find the vertical effective stress in kPa at 5m depth. 3
assume γs=26.5kN/m and that the soil above the
compute the interstitial velocity of water moving
capillary action rise and ground surface is partially
through the soil if it has e=.6 and i=.0018cm/hr 15) a test is set up as shown in the figure below.
compute the rate of flow through the aquifer in
saturated at 50% c)
find the vertical effective stress in kPa at 10m depth. assume γs=26.5kN/m3 and that the soil above the capillary action rise and ground surface is partially saturated at 50%
19) a saturated clay having a thickness of 20m has a void ratio of .68 and sg of 2.7 a)
compute the density of clay
hydraulics and geotechnical engineering 2003-2012 zherrinore..
b)
compute the total vertical stress at the bottom
c)
compute the effective stress at the bottom
20) a thick layer of clay underlies a sand formation having a thickness of 4.5 m. the groundwater is located 2n below the ground surface. sp.gr. of sand and clay is 2.65 with
a)
determine the depth of the footing
sand having an average void ratio of .52. the clay has
b)
determine the increase in pressure in the soil when
water content of 42% degree of saturation above the water table is .37
the tank is filled with oil c)
determine the settlement of the clay layer. assume
a)
compute the unit wt of sand above the water table
that the swell index is equal to 1/5 of the comp.
b)
compute the total stress at a depth of 10m below
index
the ground surface c)
26) two footings rest in a layer of sand 2.7m thick. thr
compute the effective stress at a depth 10m below
bottom of the footings are .90m below the ground
the ground surface
surface. beneath the sand layer is a 1.8 m clay layer.
21) a saturated clay layer has a thickness of 10m with water
beneath the clay layer is hard pan. the water table is at a
content of 51% and sg=2.72
depth of 1.8m below the ground surface. void ratio of
a)
compute the unit wt of the clay
clay is 1.03
b)
compute the ottal stress at the bottom
c)
compute the effective stress at the bottom
22) a given soil layer has a dry unit wt of 14.72 kn/m3 and a saturated unit wt of 20.12 kn/m3 . the ground water table is located 2m below the ground surface a)
what is the total stress at point A 4.5 m below the ground surface
b)
what is the pore pressure at point A 4.5 m below the ground surface
c)
a)
compute the stress increase in the center of the clay
what is the effective stress at point A 4.5 m below
layer,assume that the pressure beneath the footing
the ground surface
is spread at an angle of 2 vertical 1 horizontal
23) a uniform soil deposit has a dry unit wt of 15.6 Kn/m3
b)
determine the size of footing B so that the
and a saturated unit wt of 17.2 Kn/m3. the ground water
settlement in the clay layer is the same beneath
table is at a distance of 4m below the the ground surface.
footings A and B. footing a is 1.5m
point A is at a depth 6 m below the ground surface
c)
determine the settlement beneath footing A
a)
compute the effective stress at A
b)
if the water table goes up by 3.5 m, compute the
resting on a sand layer as shown on the figure. unit wt of
effective stress at A
sand above the water table is 17.31 kN/m and has a
in comparison to question 1 and 2, what will happen
saturated unit wt of 18.10 kn/m below the water table.
to the effective stress at A if the ground water level
the sand overlies a clay layer 1.2m thick having a
will rise up to the ground surface
saturated unit wt of 16.50 kn/m and a void ration of 1.7
c)
24) from the given soil profile shown, the ground surface is subjected to a uniform increase in vertical pressure of 12n/cm
27) a square footing 3mx3m carries a column load of 3500 kn 3
3
3
compression index:Cs=.07, Cc=.35 assume a vertical stress distribution of 2v:1h
2
a) a)
compute the buoyant unit wt of clay
b)
compute the overburden pressure at the mid-height compute the total settlement due to primary
the
preconsolidation
pressure
Pc
if
OCR=2.0 b)
of the clay c)
compute
compute the total effective stress at the center of the clay layer
c)
consolidation
calculate the settlement due to the consolidation of the clay layer when it is overconsolidated
25) a tank shown in the figure has an inside diameter of 8m
28) a retaining wall 8m high is supporting a horizontal backfill
and a height of 6m. it is used as a storage of oil with
having a dry unit wt of 1600 kg/m . the cohesionless soil
sg=.80. the combined wt of the empty tank and the
has an angle of friction of 33°
footing is 2800 KN
a)
3
compute the rankine active force on the wall
hydraulics and geotechnical engineering 2003-2012 zherrinore..
b)
compute the rankine active force on the wall if the
35) a soil specimen is subjected to a triaxial test. the soil
water table is located at a depth of 3.5m below the
specimen is cohesionless. if the shear stress that causes
ground surface. the sat unit wt is 18.7 kn/m c)
3
failure is 300kpa and the normal stress at failure is only
compute the location of the resultant active force
375 kpa
from the bottom for the second condition
a)
determine the angle of shearing resistance
b)
determine the angle that the failure plane measured
29) a vertical retaining wall 6m high retains a horizontal backfill having the following properties: void ratio=.60
from the major principal plane c)
sG=2.6 water content=24%
determine the total axial stress at which failure is expected to occur
36) the max stress that causes failure of a cohesive soil
Angle of internal friction=25°
specimen in a triaxial test is equal to 220 kpa. the angle
a)
compute the magnitude of the active force acting on
of friction is equal to 25°. if the deviator stress at failure
the wall if the water table is on the ground surface
is equal to 140kpa
which is on level with the top of the wall
a)
compute the confining chamber pressure
compute the magnitude of the active force acting on
b)
compute the cohesion of soil
the wall if the water table is located at a depth of 3m
c)
compute the shearing stress at the point of the
b)
from the ground surface c)
compute the magnitude of the active force if the water table is at the bottom of the wall.
30) a consolidated drained triaxial test was conducted on a
failure plane 37) the following data were obtained from a triaxial test of a normally
consolidated
soil,
deviator
stress
failure=800kpa, angle to failure plane from the major
normally consolidated clay. the results were as follows
principal plane=63°
chamber confining pressure=138kpa
a)
compute the shearing stress at the plane of failure
deviator stress=258kpa
b)
compute the normal stress at the plane of failure
a)
compute the friction angle of the soil
c)
compute the value of the confining pressure
b)
compute the normal stress at failure
c)
compute the shear stress at failure
31) a cohesionless soil has a friction angle of 30° and a
at
38) a .36 m square prestressed concrete pile is to be driven in a clayey soil as shown in the figure. the design capacity of the pile is 360KN, with FS=2
deviator stress of failure of 400kpa a)
find the angle that the failure plane makes with the major principal plane
b)
find the confining pressure
c)
finds the shear stress at the point on the failure plane
32) a cohesive soil specimen has a shearing resistance equal to 28° and a cohesion of 30kpa. if the max shearing stress of the soil is equal to 70kpa
a)
compute the end bearing capacity of pile
a)
b)
compute the skin friction expected to develop along
compute the lateral pressure in the cell for a failure to occur
b)
compute the maximum principal stress to cause failure
c)
the shaft of the pile c)
compute the length of pile if α=.76
39) a .30mx.30m concrete pile 22m long is driven in a clayey
compute the normal stress at the point of max.
soil having an unconfined compressive strength of 110
shear
kn/m . the unit wt of the clayey soil is 18kn/m . frictional
33) in a triaxial test fpr normally consolidated soil, the
2
constant is .76 due to skin friction. assume FS=2 and
normal stress at failure is equal to 465kpa and the shear
Nc=9
stress at failure is equal to 350kpa
a)
compute the capacity of the pile due to skin friction
a)
compute the angle of friction
b)
compute the angle of the failure plane with the
b)
compute the end bearing capacity
major principal axis
c)
compute the design capacity of the pile
c)
compute the max principal stress at failure
34) in the triaxial test for normally consolidated soil, the deviator stress is equal to 340 kpa and the angle of the failure plane makes with the major principal plane is equal to 60° a)
compute the shearing stress at the plane of failure
b)
compute the normal stress
c)
compute teh value of teh confining pressure
3
only
40) a .3m square concrete pile is to be driven at a site where soil conditions are as indicated in the figure. if a penetration of 14m is assumed
hydraulics and geotechnical engineering 2003-2012 zherrinore..
a)
what total skin friction is expected to develop along the embedded length of the pile
b)
what are these properties of soil
b)
determine the plasticity index
c)
what is the liquidity index if w=30%
46) From the given table shows the LL and PL of soil x and y
what is the design capacity of the pile if it has a
Soil Liquid limit X 47 Y 70 a) find the PI of soil x
factor of safety of 2
b)
find the PI of soil y
c)
what is the purpose of the test
compute the total end bearing capacity of the pile if Nc=9
c)
a)
41) a pile group consists of 12 piles with a diameter f .3 m
Plastic limt 22 38
and a pile length of 12 m is shown in the figure. the piles
47) a 300 mm diameter test well penetrates 27m below the
are spaced in a 3pile by 4 pile rectangular configuration
static water table. after 24 hours of pumping at 69l/sec
with a pile spacing of .6m center to center of piles. the
the water level in the observation well at a distance of 95
piles are driven into the clay that has the given
m from the test well is lowered .5m and the other
characteristics. the piles penetrate a soft clay(c=20kpa)
observation well at a distance of 35m from the testwell,
medium dense clay(c=56kpa) and stiff clay(c=95 kpa), use
the drawdown is 1.1m
α=1 for soft and medium dense clay and .5 for stiff clay.
a)
what is the rate of flow in m /day
b)
compute the coefficient of permeability of the
3
aquifer in m/day c)
2
compute the transmissibility of the aquifer in m /day
48) a 7m deep braced cut in sand is shown. in the plan, the struts are placed at a spacing of 2m center to center. using pecks empirical pressure diagram, compute the following
a)
determine the capacity of the pile group based on the single pile failure mode
b)
determine the capacity of the pile group based on block failure mode
c)
determine the minimum center to center spacing of piles to achieve 100% efficiency
42) a nine pile group consists of .30 m diameter friction
a)
strut load at level A
concrete piles 12m long. the piles are driven into clay
b)
strut load at level C
c)
strut load at level B
2
having a cohesion of 50 kn/m and the unit wt of clay is 19.2. the spacing of piles is .75m center to center.
49) the hydraulic gradient for quicksand condition is equal to
assuming Nc=9 and α=1
1.13 with a void ratio of .50. the moist unit wt of soil is
a)
find the allowable group pile capacity based on
19.04kn/m
individual pile failure using FS=3
a)
compute the SG of the soil
b)
find the block capacity of pile group using FS=3
b)
compute the dry unit wt of the soil
c)
find the minimum spacing in order to achive 100%
c)
compute the water content of the soil
efficiency 43) a group of friction piles is shown in the figure. the total
3
50) the results of a constant head permeability test for a fine sand and sample having a diameter of 150mm and a
load on the pile less the weight of the soil displayed by
length of 150mm are as follows
the foundation is 1800kn. thickness of silt is 2m and that
constant head difference=40cm
of clay is 16m
time of collection of water=83sec
a)
determine the effective overburden pressure at
weight of water collected=39 g
midheight of the consolidating clay
a)
b)
determine the compression index of the clay layer
c)
determine the settlement of the pile foundation
44) a soil sample was determined in the laboratory to have a
find the hydraulic conductivity
51) from a constant laboratory permeability test on a fine sand the following are given length of specimen=17cm
liquid limit of 41% and a plastic limit of 21.1%. if the
diameter of specimen=5.5cm
water content is 30%, determine the following
constant head difference=40cm
a)
plasticity index
weight of water collected=50g
b)
liquidity indez
duration=12sec
c)
characteristic of the soil
a)
45) given the LL of soil=58% and its PL=8%
find the hydraulic conductivity
hydraulics and geotechnical engineering 2003-2012 zherrinore..
52) an anchored sheet pile supports a mass of soil 7.3m high with a horizontal surface. the angle of friction of the soil
100 200
.905 .815
3
is 31° with a unit wt of 1.96g/cm . the total height of the sheet pile is 10.5 m which is supported by an anchor bolt placed 1.2 m below the ground surface which has a spacing of 3m center to center a)
compute the active force
b)
compute the fraction of the theoretical-maximum passive resistance of the total embedded length a)
which must be mobilized for equilibrium c)
calculate the average effective stress on the midheight of clay layer
compute the tension in the anchor bolt
53) a cantilever sheet pile is 8,2 m long with a depth of
i)
60.74kPa
embedment of 3.2m. angle of friction of the soil
ii)
42.24
supported by the sheet pile is 34° and has a unit weight
iii) 36.36
of 1.91g/cc. there is water table below the base of the
iv) 69.23
sheet pile
v) b)
78.95
determine the compression index cc
a)
compute the active force acting on the sheet pile
b)
compute the max passive force acting on the sheet
i)
.213
pile
ii)
.452
compute the theoretical passive force that must be
iii) .374
mobilized to ensure stability
iv) .465
c)
54) from the figure sown, the soil has a unt wt of 18kn/m
3
2
and undrained shear strength cu=20kN/m . the slopes
v) c)
.299
if the average effective stress on the clay layer is
makes an angle of 60° with the horizontal, assume a
increased(Po+∆P) to 115kPa, what would be the
stability number m=.185
total consolidation settlement? i)
123.65mm
ii)
104.6
iii) 158.74 iv) 116.35 a)
compute the stability factor
b)
compute the maximum depth up to which the cut
c)
v)
92.56
59) a tube having a cross sectional area of 100 sq.cm
could be made
contains three layers of soil having given hydraulic
compute the angle that the failure plane makes with
conductivities as shown in the tabulation. the rate of
the horizontal if BC=8m
water supplied to maintain a constant head of 400mm is
55) a piece of metal weighs 350N in air and when it is submerged completely in water, it weighs 240N
3
3
cm.sec
a)
find the volume of the metal
a)
compute the value of Ka
b)
find the specific wt of the metal
b)
compute the value of Hb
c)
find the specific gravity of the metal
c)
compute the value of Kc
56) a wooden storage vat full of oil sp. gr=.80 is in the form of frustum of a cone 2m diameter at the top and 4m
60) a wooden buoy of sg=.75 floats in a liquid with sg=85 a)
what is the percentage of the volume above the
diameter at the bottom and 3 m high. it is provided with
liquid surface to the total volume of the buoy
2 steel hoops one at the top and one at the bottom
i)
13.6
a)
compute the hydrostatic force on the side op the
ii)
14.1
container
iii) 15.6
b)
how high is the said force above the bottom
iv) 12.3
c)
compute the force on the bottom hoop
v)
57) a vat holding paint(SG+.8) is 8m long and 4 m deep and
b)
11.8
if the volume above the liquid surface is .0145m
has a trapezoidal cross section 3m wide at the bottom
what is the weight of the wooden buoy?
and 5m wide at the top
i)
.698kN
a)
compute the weight of the paint
ii)
957
b)
compute the force on the bottom of the vat
iii) .905
c)
compute the force on the trapezoidal end panel
iv) .789 v)
58) from the figure shown, the clay is normally consolidated. a laboratory consolidation test on the clay gave the Pressure(kPa)
c)
Void ratio, e
3
.821
what load that will cause the buoy to be fully submerged?
following results
-
291.21cm /hr. if the value of Ha=300mm and Kb=4x10
i)
.121kN
hydraulics and geotechnical engineering 2003-2012 zherrinore..
ii)
.151
that the two edges of the square would be horizontal in
iii) .216
order that the center of pressure shall be 8cm from the
iv) .178
center of gravity.
v)
a)
.236
61) the reading of a Toyota 6x-2003 fuel gage is proportional
how far below the water surface should the upper plate be submerged?
to the gage pressure at the bottom of the tank as shown
i)
5.258
on the figure. the tank is 32m deep. unit wt of gasoline is
ii)
7.875
3
3
6670N/m and that of air is 11.8N/m . unit weight of water is 9790 N/m a)
iv) 8.715
determine the gage reading when the tank is full of gasoline
b)
v) b)
9.875
what is the distance of the center of pressure from
i)
2231.2kPa
the water surface
ii)
2056.7
i)
10.365
iii) 2365.8
ii)
6.271
iv) 2134.4
iii) 8.784
v)
iv) 7.265
2518.6
how many cm of air remains at the top when the gage indicates full if the tank is 32 m deep and is
v) c)
9.455
determine the hydrostatic force acting on the plate
contaminated with 3cm of water
at this position
i)
2.15cm
i)
748.59
ii)
1.87
ii)
827.27kN
iii) 1.41
iii) 936.65
iv) .26
iv) 615.48
v) c)
iii) 6.154m
3
1.12
v) 2
if the tank is .5m , find the volume of the gasoline to
889.99
64) an open cylindrical vessel 1 m in diameter contains water
fill up the tank
at a depth of 3.56m.
i)
60liters
a)
ii)
70
if it is rotated at a speed of 80rpm about its vertical axis determine the least depth of the vessel so that
iii) 90
no water will be spilled out
iv) 80
i)
4
v)
ii)
3
50
62) a tank with vertical sides is 1.2 m square, 3.0 m deep and
iii) 5
is filled to a depth of 2.7m with water. a cube of wood
iv) 6
having a specific gravity of .5 measuring 60 cm on the
v)
edge is placed in the water so that it will float a)
b)
c)
b)
2
if the vessel is rotated at 120rpm, how much water
find the weight of volume of water displaced
will be spilled out?
i)
2.36
i)
425
ii)
1.75
ii)
486
iii) .26
iii) 465
iv) 3.85
iv) 405
v)
v)
1.0
determine the depth that the water will rise inside
c)
444
if the vessel is rotated at 140 rpm, what would be
the tank from its original water level
the pressure at the center bottom of the tank?
i)
.025m
i)
12.36kPa
ii)
.015
ii)
10.35
iii) .075
iii) 15.72
iv) .123
iv) 18.18
v)
v)
.042
what will be the change in pressure on one side of the tank? i)
1.451
ii)
2.875kN
22.36
65) from the figure shown, the gate is 1m wide and is hinged at the bottom of the gate
iii) 2.417 iv) 3.052 v)
.051
63) a square plate having one of its side equal to 3m is immersed in a water surface in a vertical position such
a)
compute the hydrostatic force acting on the gate
hydraulics and geotechnical engineering 2003-2012 zherrinore..
b)
compute the location of the center of the pressure
how soon after will the water surface be 4m apart? 2
of the gate to the hinged c)
c)
71) an orifice having an area of .00785m is attached to a
Determine the minimum volume of concrete 3
vertical side of a cylindrical tank having a diameter of 4m.
(γ=23.6kN/m ) needed to keep the gate in a closed
the weight of the water discharged in 1 min and 40 sec is
position.
22563N under a constant head of 1.2m. the jet strikes a
66) a vertical plate shown is submerged in vinegar having a sg=.80. assume γw=9.79kN/m
3
point 1.92m horizontally from the vena contracta and .80m vertically below the orifice a)
find the coefficient of velocity
b)
find the coefficient of discharge
c)
compute the coefficient of contraction
72) two closed compartments A and B are connected by an orifice having a diameter of 140mm diameter at its sides. at compartment A, it contains water at a depth of 3m a) b) c)
find the depth of the center of pressure of section A
above the orifice and a pressure on top of it equal to
from the liquid surface
50kPa. on the other compartment, it contains water at a
find the magnitude of the hydrostatic force on one
depth of 2m above the orifice and a pressure of 15kPa on
side of the plate
top of the water surface. c=.86 Cv=.92
find the depth of the center of pressure of the whole section from LS
67) a vertical rectangular gate as shown is 2m wide, 6 m high is hinged at the top has oil sg=.84 standing 7m deep on one side, the LS being under pressure of -18.46kPa a)
compute the discharge thru the orifice
b)
compute the headloss
c)
compute the power loss in watts
73) a trapezoidal channel has a bottom width of 6m and side slopes of 2 horizontal and 1 vertical. when the depth of 3
a)
compute the hydrostatic force acting on the gate
flow is 1.2m, the flow is 30.40 m /s
b)
how far is the force acting below the hinge
a)
compute the specific energy
c)
how much horizontal force applied at the bottom is
b)
compute the slope of the channel if n=.014
needed to open the gate
c)
compute the average shearing stress at the
68) the tank in the figure is 3m wide into the paper. neglecting atmospheric pressure. compute the following. use γw=9.79kN/m
3
boundary 74) the cross section of a right triangular channel is shown with a coefficient of roughness n=.012. if the rate of flow 3
a)
vertical force on the quarter circle panel BC
is 4m /s
b)
horizontal force on the quarter circle
a)
det. the critical depth
c)
resultant force on the quarter circle panel BC
b)
det. the critical velocity
d)
angle that the resultant makes with the horizontal
c)
determine the critical slope
69) a square plate having one of its side equal to 3m is
75) a rectangular channel 6m wide has a constant specific
immersed in a water surface in a vertical position such
energy of 2.2
that the two edges of the square would be horizontal in
a)
calc the critical depth
order that the center of pressusre shall be 10 cm from
b)
cal the critical velocity
the center of gravity
c)
cal the critical slope if n=.012
a) b) c)
how far below the water surface should the upper
3
76) a rectangular channel carries a discharge of 17.6m /s
plate be submerged
when flowing 1.2 m depth. if the width of the canal is
what is the distance of the center of the pressure
10m
from the water surface
a)
compute the min specific energy
determine the hydrostatic force acting on the plate
b)
compute the normal slope if n=.014
c)
compute the average shearing stress of the
70) two open cylindrical tanks are connected by an orifice 2
having a cross sectional area of .004m . tank A is 8m in
boundary
diameter and its water level is 10 m above that of B
77) water flows through an almost level channel 3.0 m wide
whose diameter is 5m. if the coefficient of discharge is
at 12m /s. the depth gradually increase from 1.0m to
.60
1.1m for a length of flow of 5m
3
a)
find the discharge flowing in the orifice
a)
what is the HL
b)
how long will it be before the water surface are at
b)
what is the slope
the same level
c)
compute for n
hydraulics and geotechnical engineering 2003-2012 zherrinore..
78) a pump draws water from reservoir A and lifts it to a
b)
find the water hammer pressure for instant closure
reservoir B as shown. the loss of head from A to 1 is 3
c)
how much time should be allowed for closing the
times the velocity head in the 150mm pipe and the loss of head from 2 to B is 20 times the velocity head in the
valve to avoid water hamer? 83) the error in the measured head in a channel is equal to 3
100mm pipe. when the discharge is 20L/sec
0.018m. if the discharge flowing the channel is .6m /s. compute the following a)
%error if a suppressed rectangular weir is used with length of weir is equal to 4.2m
b)
% of error if a cipolletti weir having a length of weir of 4.6m
c)
% of error if a right triangular weir is used#
a)
compute the horse power output of the pump
84) a 600mm diameter steel pipe, 10mm thick carries water
b)
compute the pressure head at 1 compute the
under a head of 325m
pressure head at 2
a)
79) two reservoirs A and B have elevatons of 250m and 100m respectively. it is connected by a pipe having a diameter
pipe b)
of 250mm and a length of 100m. a turbine is installed at a point in between the reservoirs A and B. if c=120,
determine the actual stress in kN per meter length of if the head is increased to 500m, what is the actual stress on the wall in Mpa
c)
if the head is increased to 500m, what thickness is
compute the ff if the discharge flowing in the pipe is
required assuming an allowable tensile stress of
150liters/sec
113mPa and efficiency of the connection is 80% 85) the velocity of oil flowing thru a 30mm diameter pipe is equal to 2m/s. oil has kinetic viscosity of 5x10
-5
2
m /s. if
the pipe has a length of 120m a)
compute the Reynolds number
b)
compute the friction factor
c)
compute the headloss of the pipe
86) a liquid having a Reynolds number of 1900 flow thru a a)
headloss of pipe due to friction
200 mm diameter pipe 150m long. the headloss of the
b)
head extracted by the turbine
pipe due to friction is 22m
c)
power generated by turbine
a)
compute the friction factor
80) a rectangular channel 5.4m wide by 1.2 m deep is lined
b)
compute the kinematic viscosity
with a smooth stone well and has a hydraulic slope of
c)
compute the rate of flow in l/sec
.001. using n=.012
87) a closed cylindrical tank having a radius of .6m and a 3
a)
what is the capacity of the channel in m /s
height of 4m is full of water under a pressure of 196.2
b)
what savings in earth excavation could have been
kPa. the metal side is 3mm thick. if the vessel is rotated
offered by using more favourable proportional but
at 200rpm
adhering to the same delivery and slope
a)
compute the total pressure on the side of the wall
what savings in lining per meter length could have
b)
compute the total pressure against the top
been offered by using more favourable proportional
c)
compute the maximum intensity of the hoop on
c)
but adhering to the same delivery and slope 81) a trapezoidal canal has a base width equal to 6m which
tensile side 88) a footing 6m square carries a total load, including its own
carries water flowing at velocity of .8m/s
weight of 10000 KN. the base of the footing is at a depth
a)
compute the discharge in the canal if the side are
of 3m below the ground surface. the soil strata at the site
sloping at an angle of 45° such that it will have a
consists of a layer of stiff fully saturated clay 27.5m thick
minimum seepage
overlying dense sand. the average bulk density of the clay
b)
compute the discharge in the canal for MES
is 1920kg/m and its average shear strength determined
c)
compute the discharge if the depth of the canal is
from undrained triaxial test is 130kN/m .
only 2/3 of the base width and has side slopes of 1:1
3
2
from the table,
82) water from a reservoir flowing througha non rigid
a)
determine the gross foundation pressure
600mm pipe with a velocity of 2m/s is completely
b)
determine the net foundation pressure
stopped by a closure of a valve situated 150 m from the
c)
calculate the factor of safety of the foundation
reservoir. assume that the pressure increases at a
against the complete shear failure under the
uniform rate and that there is no damping of the
undrained
pressure wave. the pipe has a thickness of 20mm. bulk
foundation may be neglected
9
modulus of water is 2.2x10 mPa and modulus of 11
elasticity of steel is 1.4x10 mPa a)
compte the velocity of sound of water
condition.
side
cohesion
on
the
89) a square footing has a dimension of 1.2m by 1.2m and has its bottom 1m below the ground surface
hydraulics and geotechnical engineering 2003-2012 zherrinore..
a)
if the ground water table is located at a depth of 1.2m below the ground surface. compute the allowable load that the footing could carry if it has a factor of safety of 3
b)
find the ultimate bearing capacity of the soil if the ground water table is at the bottom of the footing
c)
find the ultimate bearing capacity of the soil if the ground water table is .5m above the bottom of the footing
90) Andrew s. rebuyas
