Soils, Foundations, and Settlements - Answers

These are the marked pages:

AASHTO Soil Classification - Table 35.4 - Page 35-5

Sieve Sizes - Table 35.2 - Page 35-3

Angle of Failure - Equation 35.41 - Page 35-26

Soil Indexing Formulas - Table 35.7 - Page 35-9

While other stuff in the chapter is useful - I think that marking it would be more hindering than helpful during the test.


Today's answers:

Soils, Foundations, and Settlements - Questions

1. A sample moist soil has the following attributes:

Volume = 0.52 ft^3 (as sampled)
Mass = 56.75 lbm (as sampled)
= 48.7 lbm (after oven drying)
SG of solids = 2.7

After drying the soil was run through a set of sieves.

Sieve ---------- % finer by mass
½ in ----------- 52
No 4 ---------- 37
No 10 ---------- 32
No 20 ---------- 23
No 40 ---------- 11
No 60 ---------- 7
No 100 ---------- 4

a) what is the density of the in situ soil?
b) What is the unit weight of the in situ soil?
c) What is the void ratio of the in situ soil?
d) What is the porosity of the in situ soil?
e) What is the degree of saturation of the in situ soil?
f) What is the uniformity coefficient?
g) What is the coefficient of curvature?
h) What is the USCS classification?
i) What is the AASHTO classification?


2. A triaxial shear test is performed on well drained sand. At failure the normal stress was 6300 lbf/ft^2 and shear stress was 4200 lbf/ft^2.
a) what’s the internal angle of friction?
b) What is the maximum principal stress?

3. A sample of sand has a relative density of 39% with solids SG = 2.7. The minimum void raito is 0.46 and the maximum is 0.96
a) what is the specific weight of the sand in saturated condition?
b) If the sand is compacted to a relative density of 70%, what will be the decrease of thickness of a layer 4 ft thick.

Soils, Foundations, and Settlements

This is our first 2 day topic.

I am going to break it into 2 sections

Chapter 35 in Lindeburg.

These are the chapters in the practice problems book:
Chapter 35 – Soil Properties and Testing - 14 problems

Pollution and the Environment - Answers

I marked the following pages:

Relative Oxidation Powers - Table 34.1 - Page 34-4

And today's answers are:

Pollution and the Environment - Questions

1. Given a landfill for a town with a population of 12,000, expected to double in 15 years. The town has a 35 ac landfill, to be converted into a park in 20 years. Solid waste is generated at 6 lbm/capita-day. Average compacted density of landfill will be 1000lbm/yd^3. Disregard soil addition for cover and cell construction. How long will it take to fill the landfill to 6ft.

2. Biosludge is dewatered to 70% water by weight. Solids have higher heating value of 6600 btu/lbm. Dewatered sludge enters a fluidized-bed combustor with an 1000°F windbox at the rate of 14,000 lbm/hr.
a) find the specific feed characteristic.
b) Find the approximate energy in btu/hr needed by the auxiliary fuel supply

Pollution and The Environment

Chapter 31, 32, 33, and 34 in Lindeburg.

Only one of these chapters has problems - so I will list the other chapters anyway, but rather than do problems, I will read the chapters and maybe make a summary of a few high points. Or look for examples from within in the text.

These are the chapters in the practice problems book:
Chapter 31 – Municipal Solid Waste - 2 problems
Chapter 32 - Pollutants in the Environment - 44 sections of reading
Chapter 33 - Disposition of Hazardous Materials - 3 sections of reading
Chapter 34 - Environmental Remediation - 53 sections of reading

Wastewater - Answers

I did not mark any pages. Should a BOD question come up on the test, I will just have to look in the index. Otherwise there would be too many to mark.

And today's answers are:

Wastewater - Questions

1. A town of 11,000 people (130 gpcd) has its own primary treatment plant.
a) What mass of total solids should the treatment plant expect?
b) If the town is 5 mi from the treatment plant and 425 feet above it in elevation. What minimum pipe size should be used, assume the pipe flow full?

2. The BOD of raw sewage of a plant serving 21,000 is 350 mg/L. The BOD loading is 0.18 lbm/day. 25% of the BOD is removed by settling. One single stage high rate trickling filter is to be used to reduce effluent to 75 mg/L. Recirculation is from the filter to the primary settling effluent. Ten States’ Standards is in effect.
a) What is the design flow rate?
b) Using the above design flow rate, what is the total organic load on the filter?
c) What is the plant efficiency?

3. Waste water from a city with a population of 44,000 has daily average flow of 4.0 MGD

BOD5 at 20°C – 150 mg/L
COD = 850 mg/L
Total Solids = 950 mg/L
Suspended solids = 190 mg/L
Volatile solids = 330 mg/L
Settleable solids = 9 mg/L
pH = 7.9

Wastewater is treated with primary settling and secondary trickling filtration. Settling basins are circular, 9 feet deep and designed to a standard overflow rate of 1500 gal/day-ft^2

a) assume 2 basins in parallel, find the diameter in order to remove 35% BOD
b) What is the detention time?
c) What is the weir loading?

4. 35 m^3/day of thickened sludge with a suspended solids content of 4% and 15 m^3/day of anaerobic digester sludge with a suspended solids content of 8% are produced in a wastewater treatment plant.
a) What is the effect of the use of a filter press to increase solids content of thickened sludge to 25%?
b) What volume of digester sludge must be disposed of from sand drying beds that increase the solids concentration to 34%?

Wastewater

Chapters 28,29 and 30 in Lindeburg.

These are the chapters in the practice problems book:
Chapter 28 – Wastewater Quantity and Quality - 6 problems
Chapter 29 – Wastewater Treatment: Equipment and Processes - 6 problems
Chapter 30 – Activated Sludge and Sludge Processing - 2 problems

Water Supply - Answers

These are the pages I marked so far (I was rushed to do this today - so I will be looking at this some more and may add some marked pages):

Water Chemistry Equivalents - App 22.C - Page A-49

Settling Velocity - Figure 26.2 - Page 26-5

Mixing Physics - Section 17 - Pages 26-8 & 9


And the Answers to today's questions:

Water Supply - Questions

1. Lab analysis of a water sample is as follows:

Ca++ = 75.0 mg/L
Mg++ = 18 mg/L
Na+ = 28 mg/L
K+ = 39 mg/L
pH = 7.7
HCO3- = 275 mg/L
SO4-- = 72 mg/ L
Cl- = 50 mg/L

a) What is the hardness in terms of calcium carbonate equivalent?
b) Assume compounds are formed proportionally to the relative concentrations of ions. What is the concentrations of calcium bicarbonate?
c) What is the concentrations of magnesium bicarbonate?
d) What is the concentrations of magnesium sulfate?
e) What is the amount of lime (CaO) needed to remove calcium carbonate hardness?

2. A spherical sand particle has an SG of 2.5 and a diameter of 1.1 mm. Determine the settling velocity.

3. Water supply for a town of 14,000 people is taken from a river. Average consumption is 115 gpcd and the water has the following attributes:

turbidity = 25 to 95 NTU (varies)
total hardness = less than 60 mg/L as CaCO3
coliform count = 250 to 950 for 100 mL (varies)

a) what capacity should the distribution and treatment system have?
b) If application rate is 4 gal/min, what total filter area is required?
c) If a Chlorine dose of 2.5 mg/L is required for desired residual, how much Cholrine is required every 24 hours?

Water Supply

Chapter 25 and 26 in Lindeburg.

These are the chapters in the practice problems book:
Chapter 25 – Water Supply Quality and Testing - 4 problems
Chapter 26 – Water Supply Treatment and Distribution - 13 problems

Hydrology - Answers

I only marked a couple pages for this section.


Hydrographs - Section 10 - Page 20-9
Steel Formula Coefficient for Rainfall Intensity - Table 20.2 - Page 20-5
Flow Nets - Section 16 - Page 21-8

I did finally register for the test - the price went up a little over $30 - which is irritating - but now I'm commited anyway.

And the answers to today's questions:

Hydrology - Questions

1. A 2 hour storm over 110km^2 area produces a total runoff volume of 3.9x10^6 m^3 with a peak discharge of 250 m^3/s

a) What is the total excess precipitation?
b) What is the unit hydrograph peak discharge?

2. A class A evaporation pan located near a reservoir shows a 1 day evaporation loss of 0.7 in. If the pan coefficient is 0.75, what is the approximate evaporation loss in the reservoir?

3. A well extends from the ground surface at elevation 400 ft through a gravel bed to a layer of bedrock at elevation 300 ft. The screened well is 1450 ft from a river whose surface level is 375 ft. The well is pumped by a 10 in diameter schedule 40 steel pipe which draws 130,000 gal/day. The hydraulic conductivity is 1500 gal/day-ft^2. The pump discharges into a piping network whose friction head is 90 ft. What net power is required for steady flow?

Hydrology

Chapter 20 and 21 in Lindeburg.

These are the chapters in the practice problems book:
Chapter 20 – Meteorology, Climatology, and Hydrology - 11 problems
Chapter 21 – Groundwater - 5 problems


I do not want to get in trouble with copy rights here, so I will not be posting problems directly from the book. These books are worth purchasing, as well as the 6 minute solutions books.

TO DO:
Minimum - Read through all the problems and US customary solutions (SSI solutions are given, but the test is in US customary units, you should go ahead and get used to that now.)





Work several of the problems, especially ones you may not be familiar with.





If you have time, look through the book for example problems, and or reading for information you didn't understand from the problems and solutions.

Open Channel Flow - Answers

I’m going to add another element. As I work through the problems, sometimes I find charts or whatever that I think I may need later on, so I’m going to tell you where I put little post-it flags and what I call them in the book - I will post this with the answers, because that's when I'll have a complete list for the chapters. This list is for everything so far, but from here on out, I will just post what I’m adding for the current chapters.

Fluids, Conduit Flow, and Pumps

Moody Diagram - Figure 17.4 - Page 17-6
Hydraulic hp equations - Table 18.5 - Page 18-8
Ten States’ Standards - App. 29.A - Pages A66-67
Water and Air properties - App. 14.A-E - Pages A13-14
Equivalent Lengths - App 17.D - Page A-31
Darcy’s Friction Factors - App 17.B - Page A26-29

Open Channel Flow
Manning’s roughness coefficient - App 19.A - Page A-37
Basic Channel Section Properties - Table 19.2 - Page 19-3
Manning Equation - Eqn.19.3 - Page 19-4
Culvert Types - Figure 19.25 - Page 19-27
Froude # determine critical flow - Section 27 - Page 19-18
Optimum Channel Dimens - Section 12 - Page 19-9

And now the answers to today’s problems:

Open Channel Flow Questions

1. A rectangular open channel is to be constructed with smooth concrete on a slope of 0.075. The design flow rate is 18m^3/s. The channel design is optimum. What are the channel dimensions?

2. A circular sewer pipe (n=0.012) is installed on a 1.5% grade. Manning coefficient (n=0.013). Maximum full flow capacity = 4 ft^3/sec. Use a 12 in pipe.
a) What is the full flow capacity
b) What is the full flow velocity

3. A trapezoidal open channel with smooth concrete on a slope of 0.075, design flow rate = 18 m^3/s. Assume optimum design. What are the dimensions?

4. A Hydraulic jump forms at the toe of a spillway. Water surface levels are 0.3 ft and 7 ft above the apron before and after the jump, respectively. The velocity before the jump is 55 ft/sec. Find the energy loss.

Open Channel Flow

Chapter 19 in Lindeburg.



This is the chapter in the practice problems book:

Chapter 19 – Open Channel Flow - 23 problems



I do not want to get in trouble with copy rights here, so I will not be posting problems directly from the book. These books are worth purchasing, as well as the 6 minute solutions books.



TO DO:

Minimum - Read through all the problems and US customary solutions (SSI solutions are given, but the test is in US customary units, you should go ahead and get used to that now.)



Work several of the problems, especially ones you may not be familiar with.



If you have time, look through the book for example problems, and or reading for information you didn't understand from the problems and solutions.

Fluids, Conduit Flow and Pumps - Answers

This layout seems ok, I wish you could click the picture and have it blow up...I will work on other methods. Maybe I will take pictures of my answers instead of scanning them.

Fluids, Conduit Flow, and Pumps Questions

1. Find absolute pressure, given 9.7 psi vacuum.

2. Calculate kinematic viscosity of air at 80°F and 60 psia.

3. A pipe with an inside diameter of 18 in contains water to a depth of 15in. Find the hydraulic radius.

4. Points A and B are separated by 2000 ft of new 8 inch schedule 40 steel pipe. 500 gal/min of 70°F water flows from A to B. Point B is 50 ft above point A. Pressure at B is 50psig, what is the pressure at A?

5. A cylindrical tank 30 ft tall (full) and 15 ft in diameter has a 6 inch hole in the bottom. Coefficient of discharge = 0.99 How long will it take the water to drop from 30 feet to 20 feet?

6. 1500 gal/min of 70°F thickened sludge with SG of 1.1 flows through a pump with an inlet diameter of 10 in and an outlet diameter of 6 in, centerlines at same elevation. Inlet pressure is 7 in Hg (vacuum). A discharge pressure gauge 3 ft above the pump discharge centerline reads 25psig. The pump efficiency is 85%. All pipes are schedule 40. What is the input power of the pump?

7. A double suction water pump moving 250 gal/sec turns at 800 rpm. The pump adds 15 ft of head to the water. What is the specific speed?

8. A horizontal turbine reduces 150 ft^3/sec of water from 25 psia to 5 psia. Friction is negligible. What power is developed?


**** I will post these when I write them, but before I solve them, so I have no idea if they are even solvable.****

****I will post answers within 24 hours****

Fluids, Conduit Flow, Pumps

Chapters 14, 15, 16, 17, and 18 in Lindeburg.

These are the chapters in the practice problems book:

Chapter 14 – Fluid Properties - 3 problems

Chapter 15 – Fluid Statics- 2 problems

Chapter 16 – Fluid Flow Parameters - 2 problems

Chapter 17 – Fluid Dynamics - 24 problems

Chapter 18 – Hydraulic Machines - 18 problems

I do not want to get in trouble with copy rights here, so I will not be posting problems directly from the book. These books are worth purchasing, as well as the 6 minute solutions books.

TO DO:
Minimum - Read through all the problems and US customary solutions (SSI solutions are given, but the test is in US customary units, you should go ahead and get used to that now.)

Work several of the problems, especially ones you may not be familiar with.

If you have time, look through the book for example problems, and or reading for information you didn't understand from the problems and solutions.

Schedule

New approach – review problems, not book, use book as reference to do problems. Unless there are no problems. The past 2 times I have gotten bogged down in reading the book and my reading comprehension being what it is, it's simply a waste of my time.

I am skipping the engineering economics – it’s easy stuff, one day of review should be plenty if you want to do that. I already did it back in January.

I have 52 days.

I also have a 16 ½ month old son. So time is precious.

At the very least I want to read through each problem and solution. Why? On my first attempt I remember seeing a problem that I had actually seen before. The numbers were off minimally and I was able to get the correct answer just by looking at the answer of the example and the choices for the test problem.

6 minutes solutions and ppi2pass are books and a website respectively.

Each day I will post at least a couple of problems.

So here’s the schedule:

19-Feb Fluids, Conduit Flow, Pumps
20-Feb Open Channel Flow
21-Feb Hydrology
25-Feb Water Supply
26-Feb Wastewater
27-Feb Pollution and the Environment
28-Feb Soils, Foundations, and Settlement
3-Mar Soils, Foundations, and Settlement
4-Mar Retaining Walls and Deep Foundations
5-Mar Retaining Walls and Deep Foundations
6-Mar Surveying
10-Mar Highway Curves
11-Mar Traffic and Accident Analysis
12-Mar Mixing Concrete and Concrete Beams
13-Mar Mixing Concrete and Concrete Beams
17-Mar Steel Beams and Columns
18-Mar Steel Beams and Colum
19-Mar Structural Analysis ns
20-Mar Structural Analysis
24-Mar Lindeburg Sample Exam
25-Mar Lindeburg Sample Exam
26-Mar NCEES Sample Problems
27-Mar NCEES Sample Problems
31-Mar Special Binder *
1-Apr Special Binder *
2-Apr Binders with ppi2pass and six minute solutions - Transportation
3-Apr Binders with ppi2pass and six minute solutions - Water Resources
7-Apr Binders with ppi2pass and six minute solutions - Environment
8-Apr Binders with ppi2pass and six minute solutions - Geotechnical
9-Apr Binders with ppi2pass and six minute solutions - Structural
10-Apr Binders with ppi2pass and six minute solutions - Structural

*The special binder is a binder that a friend used to help him pass, I will share parts of it with you.

You're doing what?

Ok, so I have found that I'm having a heck of a time studying for the PE exam.

I have also found that I like reading blogs.

So, I've decided to combine the two.

I am due to take the Civil PE exam in April in Texas. For the 3rd time. Hopefully it's the final time.

So what I'm going to try to get done here is a study blog.

I originally created a schedule using Lindeburg's books. And the ppi2pass.com suggested schedule.

It looks like this:
I have fallen miserably behind.

But here's my new plan. I have also obtained a lot more materials and have changed my approach. So I'm basically going to tell you about what I'm studying on here and then I'm going to post a couple problems.

I should tell you that this blog will be aimed at the breadth civil questions and the depth structural questions.

I aim to have a new schedule and first problems out today.