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CIVIL ENGINEERING LICENSURE
ET RRAMINATIONS
HYDRAULICS and
GEOTECHNICAL ENGINEERING
NOVEMBER 2022
TE er
A confined aquifer is recharged by a
continuous supply of water from a certain
source. The average thickness of the aquifer
was determined to be 25 m. and the average
width is 4 km. The hydraulic .conductivity
(coefficient of permeability) of the aquifer was
obtained at 50 m per day and its porosity is
0.25. The piezometric heads on two wells 1
km apart are 65 m. and 60 m. from a common
reference datum. From the given data, obtain:
the rate of flow through the aquifer in
cu.m. per day.
Evaluate the seepage velocity in meiers
per day.
Evaluate the time of travel, in days, from
the head of the aquifer to point 4 km
downstream.
8 8
e
A= 25(4000)
A= 100000 m2
Q=KiA
Q= (40)(5x 10°3)(100000)
Q= 20000 mday
® Seepage velocity:
= os = 0.8 m/day
Time to travel 3 km downstream:
___Distance
Seepage velociy
"08
‘= 3750 days
PP =F Ard
‘The result of a consolidated drained ti-axal |
soil fest conducted on a consolidated clay are
as follows
Chamber confining pressure = 250 kPa
Deviator stress at failure = 350 kPa
© Evaluate the angle of riction of the sol
sample in degrees.
Evaluate the shear stress on the faiute
plane in kPa.
® Evaluate the normal stress on the plane of
maximum shear in kPa.
@ q
H-189
| i éngineering Licensure Examinations
aa a
Solution:
» Angle offrction ofthe soil sample
T= 175 Cos 24.31"
T= 159 kPa
® Normal strass on the plane of maximum
shear
n= 425 kPa
eee
ROPE
A450 kn
ang 's transmitted by a column footing
7 Surface through a square footing 1.6
de esi that the force exerted
erlying soil formation spreads on 2
mata to + horizontal, evaluate the pressure
I" footing on a sol 2.7 m. below it
Solution:
450 kN
ERE
13s” 1s “Vas
42
CE Board Nov. 2022
An unconfined compression test was
conducted to a soil sample having a diameter
of 50 mm. The failure load was 65 N. What is
the value of the cohesion strength of the clay
in kPa.
Solution:
0.066
Bigot
* (0.05)
{oe
0=3361
Unconfined compression (
6 23361 KPa
Cohesion strength C :
_ 3361 _yggupa H-190
5, CE Board Nov. 2022
A triangular gate or height 1.2 m and base
0.9 m is installed in a position that its plane is
inclined 60 degrees with the horizontal with its
vertex at the top and the base is parallel to the
water surface. The vertex is at a depth of 2m
vertically below the water surface. Fresh water
is on one side of the gate.
@® Evaluate the total hydrostatic force on the
gate in kN.
® Locate the point of action of the total
hydrostatic force from the vertex on the
plane on the gate.
If the gate is Hinged at the bottom,
evaluate the force normal to the gate at its
vertex thet will be required to open it in
KN.
@
Solution:
@® Total hydrostatic force on the gate in kN.
Hinged
comer of 0,
pressure 90
h=2+0.8 Sin 60°
P=yhA
p-aeresta{$)12908)
P=14.3kN
Civil Engineering Licensure Examinations
force from the vertex on the plane on the
gate.
=06+
Solution:
XSI 8 090
os (Vn 30%
\ ji
Vv, =¥- 800
BF = V,(1.03)(9.84)
BF = 10.1043,
W=V(0.90)(2.81)
W=8829V
BF=W
10.1043 V, = 8.829 V
10.1043 (V - 500) = 8.829 V
1.2753\V = 5052.15
V= 3962 m?
TT TP eee
A right cylindrical container 4.0 m diameter is
3m. fall. A50 mm diameter hole is provided at
the bottom of the container to drain the water
When necessary. If itis full of water, how long,
in hour(s), does it take to empty the container
fom the instant the hole is opened?
Coeficient of velocity and coefficient of
| Srtraction both equal to 10.
Solution:
x
A= —(0.05)
(008)
A= 0.00196
A= Fy =m
p= Zar
4(z)(005)* /2(981)
t =5005 sec.
t= 1.39 hours
CTT ars 74
A cohesive soil sample was taken from an
‘SPT and taken to the laboratory in a glass jar.
Itwas found to weigh 145 grams. The sample
was then placed in a container having a
volume V = 500 cm? and 420 cm? of water
were added to fill the container. Evaluate the
unit weight of the soil in KN/m?.
Solution:
we 0.145(9.81)
1000
W =0.00142245 kN
V=500- 420
v= 80cm?
V = 0.00008 m?
2+R
“ 12
‘Shas 2
nO +
8= 2202"
PAP 8 TCR asd
The following table shows an approximate
correlation between the standard penetration
test (SPT) and the unconfined compression
strength of cohesive soils,
Unconfined
SPT blows Consistency
compressive
strength,
: qu(kPa)
0to2 Very soft 0-239
2to4 Soft 23.9-478
Ato8 Mediurn 478-957
8t015 Stif 957-191
48 to 34 Very Stiff 191-383,
Evaluate the approximate shear strength of
the soil if the blow count N = 6.
Solution:
2 4 478
44746 * \ 4799
8 95.7
4
4
47,90
x= 23.95
4g, =47.8+ 23.95
4g, =71.75kPa
4
esa
1.75
¢ = 35.9 kPa H-200
(ofA =f TM LAAs
‘According to the elastic theory, the vertical
stress induced flexible line load of infinite
length that has an intensity of q units/length on
the surface of a semi-infinite soil mass can be
estimated by the expression: .
gq
= 0.637 —
peel
of
= horizontal distance from the line load
Z.= depth of interest at which stress is induced
A concrete hollow block wall weighing 6 kN
per lineal meter is carried by a wall footing
0.60 m. wide.
@ Evaluate the bearing pressure in kPa
exerted by the footing onto the supporting
soil,
® Evaluate the stress in the soil caused by
the load depth equal to twice its width.
@ Evaluate the stress at a depth of 2m. and
a horizontal distance 3 m. from the line of
load.
Solution:
@ Bearing pressure in kPa exerted by the
footing onto the supporting soll
Consider 1 m. length of wall.
A=0.8(1)=0.6 m?
Civil Engineering Licensure Examinations
® Stress in the soll caused by the loag
equal to twice its width
Z=2(0.6)
Z=12m
_ 0637q
PEON
rfl]
walla]
N=1.2
p= cere) = 5.1 kPa
Stress at a depth of 2 m. and a hori
distance 3 m. from the line of load
r=3 E=2
N=21.125
+ _ 0,637q '
Re H-201
civil Engineering Licensure Examinations
_—————
Weed) lars
Alayer of clay 8.6 m thick is overlain by a”
deposit of sand 15.2 m thick to ground
surface. When the water table is at ground
surface leval, the saturated unit weight of the
sand was determined to be 21.2 kNim? for
wich its dry unit weight is 18.2 kNim3. The
seturated unit weight of the clay is 18.8 kN/m?,
When the ground water table lowered by
76 m, the degree of saturation of the sand
above the water table was lowered to 30%. At
the mi-height ofthe clay layer,
© Evaluate the effective pressure, in kPa,
before lowering of the water table.
@ Evaluate the effective pressure, in KPa,
after the lowering of the water table.
@ Evluate the effective pressure, in kPa,
when there is no water in the sand layer
but remain in moist condition at the same
degree of saturation.
Solution:
© Effective pressure before lowering of the
water table
ec ite
san) Sad
| gf21.2 kN
+
Bin) Clay
ae
{18.8 Nim
S, = 152(21.2-9.81) + 4.3(188- 961)
6, = 212 kPa
@ Effective pressure alter the lowering of the
water table
7.6m | anes
asi
va
F
43
4m] Clay Ae
sa
(6, *Se,
1+e
_ [2673 +03 (0.4408) }98t
Ya = 404405
Ya 719A KN?
st
6, =7.5 (19.1) +7.6(21.2- 981)
+4:3(18.8 -981)
0, = 270 kPa H-202 .
Civil Engineering Licensure Examinations
Se
® Effective pressure when there is no water
in the sand layer but remain in moist
condition at the same degree of saturation
Sand
5=30%
1 pei7!8:803 KN/m?
152m)
ties] OUN gg
1 sai#18.8 KN/m3
6, = 19.1(15.2) + 4.3(18.8 -9.81)
6, = 329 kPa
