Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
|www.civilengineeringacademy.com | [email protected]
BONUS THEORY & SHORT ANSWER QUESTIONS
Thanks for checking things out at Civil Engineering Academy and
sticking around to receive these additional theory questions!!
Theory questions pop up in every section of the exam and you do not
want to be caught off guard on these. Theory questions can be easy
points for you or they can be a terrible headache if you don’t have the
right resources (time suck!).
My goal with these is to challenge you in thinking about quick solutions
to problems as well as give you more practice. It is wise, especially
for the depth section, to bring in texts books that cover material you
don’t know right off hand. Those text books can be life savers.
In the end, practice makes perfect and the more exposure you get to
the type of questions that are asked the better you will be to
absolutely crush the test.
Good luck on studying!
Isaac Oakeson, P.E.
P.S. Please give me feedback ([email protected]) if
you see anything you like or you think is wonky. I really appreciate it!
|www.civilengineeringacademy.com | [email protected]
1. What will the waste water plant size (lb/day) be for a city with
10,000 people in order to handle 500 mg/L of solids? Use an average
volume per person per day to be 110 gpcd.
a) 4580
b) 5000
c) 5290
d) 4050
2. Which of the following cross sections is the most efficient for open
channel design?
a)
b)
c)
d)
|www.civilengineeringacademy.com | [email protected]
3. When is the hydraulic load the greatest on concrete formwork?
a) During pouring of the concrete
b) After the concrete cures
c) Just after pouring
d) Three hours after pouring
4. What is the following mode called?
a) PERT
b) Activity on Branch
c) CPM
d) On Node (activity on node)
Start
A B
C
D
E
F End
|www.civilengineeringacademy.com | [email protected]
5. Which test is the best for quickly determining field compaction?
a) Nuclear gauge
b) SPT
c) CPT
d) Dilatometer
6. During a seismic event, when liquefaction occurs, the shear
strength becomes:
a) Larger
b) Smaller
c) Zero
d) Remains the same
7. What is the ultimate stress of the specimen?
a) 400
b) 500
c) 700
d) 1000
100
200
400
300
500
600
700
800
900
1000
σ (
ksi)
ϵ (in/in)
0.2 0.4 0.8 1
|www.civilengineeringacademy.com | [email protected]
8. What is determined by the impact test?
a) Toughness
b) Hardness
c) Ultimate strength
d) Yield strength
9. Regarding the level of service (LOS), which of the following
statements is correct?
a) LOS remains the same throughout the day
b) There are six levels of service
c) Level F represents unimpeded flow
d) Economic considerations favor low traffic volumes
10. Find the structural number (SN) for the following designed road
base. Assume m=1.
a) 3.52
b) 2.53
c) 1.82
d) 4.10
Surface a=0.34 D=4”
Base a=0.14 D=6”
Sub Base a=0.11 D=3”
|www.civilengineeringacademy.com | [email protected]
11. What will be the absolute pressure when a pressure gage
registers a vacuum of 9 in of mercury when the atmospheric pressure
is 14.7 psi? Use SG of mercury = 13.6.
e) 10.3
f) 11
g) 9.60
h) 13.6
12. What will be the depth after a hydraulic jump in a 10 ft wide
rectangular channel if the depth of water is 5 ft and the water
discharge is 400 cfs?
a) 5 ft
b) 3.1 ft
c) 4.2 ft
d) 2.6 ft
13. What is a mass haul diagram used for?
e) Calculate free haul distance
f) To find balance points
g) Find the center of mass
h) All of the above
14. According to OSHA, what is Type “B” soil?
a) Dry rock that is stable
b) Cohesive soil with an unconfined compressive strength less than
or equal to 1000 psf
c) Cohesive soil with an unconfined compressive strength of greater
than 1000 psf and less than 3000 psf
d) None of the above
|www.civilengineeringacademy.com | [email protected]
15. An engineer has specified sulphate resistive concrete to be used
for the construction of a bridge, which type of concrete should the
contractor use?
e) Type V
f) Type IV
g) Type III
h) Type I
16. If in a truss system the number of joints is 8, the number of truss
members is 13 and there are 2 reactions. This truss is…
a) Unstable
b) Indeterminate
c) Determinant
d) None of the above
17. What type of in-situ test is suitable for sand, silt, clay and peat?
e) CPT
f) SPT
g) Field Vane Test
h) Pressure Meter Test
18. Which is not correct regarding the construction of a flow net?
e) Flow lines cannot cross other flow lines
f) Equipotential lines can cross other equipotential lines
g) Each element in the flow net should have curvilinear squares
h) Equipotential lines intersect the flow lines at right angles
|www.civilengineeringacademy.com | [email protected]
19. How many samples should be collected to estimate time mean
speed with a confidence level of +/- 1.5 if the probability is 0.95, the
number of standard deviations is 1.96 and a deviation of 7 mph?
e) 90
f) 80
g) 84
h) 1000
20. Which of the following is not correct regarding flexible pavement?
e) Structural coarse supports friction coarse
f) Friction coarse supports base coarse
g) Base coarse supports friction and structural coarse
h) Normally the base coarse is the thickest section
|www.civilengineeringacademy.com | [email protected]
10-FREE THEORY
PROBLEM SOLUTIONS:
1. Answer A.
Solve for the feed rate:
10000 people ∗110gal
person∗day∗
500mg
L∗
8.345lb
MG
1mg/L=4587 lb/day
The closest answer is 4580.
2. Answer D.
Semicircular cross sections have the smallest wetted perimeter
and because of that they have the highest efficiency. Because of the
increased cost to construct due to labor and formwork, this is not
typically built in real world practice.
3. Answer C.
The hydraulic load is greatest immediately after pouring. As
concrete begins to set it actually supports itself and reduces the force
on the formwork. Loading during pouring doesn’t have the volume
behind it to cause the greatest load. It is immediately after pouring
that causes the greatest loading.
4. Answer D.
Because nodes are used to represent activities this is an activity-
on-node model. PERT (program evaluation and review technique) is a
different way to find activity durations using statistics, and activity-on-
branch have arcs that represent activities, which this isn’t showing.
CPM isn’t correct because the activity-on-node is used to make a CPM.
|www.civilengineeringacademy.com | [email protected]
5. Answer A.
The nuclear density gauge is the fastest way to determine field
compaction. A probe with radioactive material is inserted into a hole
punched into the compacted soil, the rate of radiation penetration is
measured to give wet density (dry is calculated) and water content.
6. Answer C.
During a seismic event liquefaction can occur in saturated
cohesionless soils (sands) causing the shear strength of the soil to
become zero and liquefying. The soil behaves like water!
7. Answer D.
This is simply a stress vs. strain curve and is meant to test how
you interpret it. The ultimate stress is located at 1000 ksi. There are
other important values that could be asked so get familiar with these
stress-strain curves (yield point, fracture point, etc.).
8. Answer A.
Impact test measures the energy to fracture a sample, which is
toughness.
9. Answer B.
There are 6 levels of service and this is the only statement that is
true.
10. Answer B.
Using equation 75.29 as assuming m=1 (CERM 12th edition)
SN=𝐷1𝑎1+𝐷2𝑎2+𝐷3𝑎3= (0.34*4”)+(0.14*6”)+(0.11*3”) =2.53
|www.civilengineeringacademy.com | [email protected]
11. Answer A.
Vacuum Pressure = Atmospheric Pressure – Absolute Pressure
SGmercury=ρmercury/ ρwater
13.6= ρmercury/62.4 lb/ft³
Pvacuum=(848.6*9)/12 (divide by 12 to covert inch to ft)
=636.5 lb/ft²
Covert to psi: 636.5/144 = 4.42 lb/in²
Find absolute pressure:
4.42=14.7-Pabsolute
Pabsolute = 10.28 psi
12. Answer D.
Discharge (Q)=Area(A)xVelocity(V)
400=10*5*V
V=8 fps
2 2
1 1 12 1
2 2
21
2 4
2 8 5 51 5
2 32.2 4
2.61 ft
v d dd d
g
13. Answer D.
The mass haul diagram (MHD) is used to calculate all of the
above. MHD is a graphical representation of cumulative volume of
earthwork (yd³) on the Y-axis versus stations on the X-axis.
14. Answer C.
According to OSHA soil classification Appendix A Subpart P, soil
type B has an unconfined compressive strength of >1000 psf (0.5 tsf)
but less than 3000 psf (1.5 tsf), so the correct answer is C.
|www.civilengineeringacademy.com | [email protected]
15. Answer A.
The correct type of concrete to use is Type V.
16. Answer A.
You must solve an equation to find out if the truss system is
determinate, indeterminate or unstable using; j(joints), m(members),
r(reactions):
2j=m+r (determinate)
2j<m+r (indeterminate)
2j>m+r (unstable)
2*8=13+2
16>15 and therefore is unstable.
17. Answer A.
CPT is suitable for sand, silt, clay and peat; however, it is not
suitable for gravel and soil with gravel and cobbles.
18. Answer B.
Equipotential lines cannot cross other equipotential lines.
19. Answer C.
Use the following: (No. of std dev. X std dev)/√(no. samples) <=
error or tolerance
(1.97*7)/ √ (no. samples) = 1.5
No. samples =83.66 = 84
20. Answer B.
In a flexible pavement section the top layer is friction coarse then
structural coarse and then base coarse and normally the base course is
the thickest section.