Civil PE Prep

Cake time

2008-06-12T12:15:00.000-07:00

Yay!!! - I photoshopped a picture from a company that sells the seals and enlarged it slightly and took it to a Kroger bakery.

I passed!!

2008-06-10T14:58:00.000-07:00

I passed!

I credit some of this achievement to this blog.

I probably wouldn't have kept to my study habits as well without it, even though no one was reading it.

I am not going to divulge my score, but suffice it to say that in hindsight, I might have studied a tad more on the depth sections. I did not leave enough time to truly devote to those things. Things like indeterminate beam theories and such.

I might have made more of an effort to locate the AASHTO code that I was missing.

I'm going to see if I can get a cake in the likeness of my seal (without the numbers, because I don't have the number yet.) I'll post a picture if I manage to find someone who will do it.

I'm alive!

2008-04-14T06:40:00.000-07:00

I feel really good about the morning part of the test and not so great about the afternoon. I felt like it was the hardest afternoon of the 3 tests I've taken.

Being that I was a "pro" people are asking me a lot of questions about the test and studying. First of all...I have not passed this test yet. So asking me the best way to study, when I clearly haven't figured it out yet is just as good as asking someone who hasn't taken it how to study. But I'm going to post a few of the questions I got that I can answer, if you have any other questions you want to ask, let me know.

1. Why do second time test takers have a lower percentage passing rate than first time test takers?

Because when people fail the first time, they assume if they just plug away harder at their first approach to studying that they'll do better, because they "only" need 3 or 4 more points to pass, so the second time they try the same approach, with the same outcome. And that's when they finally change their studying habits.

2. It says that you can't have pencil marks in your reference materials; do I have to erase everything I ever wrote in pencil in my reference materials?

I cannot speak for everywhere, but in Houston, they really only care about whether you're copying the questions from the test into your reference materials. So if you keep your pointy little pencil out of your references, you'll be fine with existing marks.

3. Do I have to choose my afternoon session before even seeing the test, or do I get a sneak peak at the other sections?

You can look at all of the afternoon sessions for your general type test (i.e. all the different civil afternoon session is you're taking the civil, or all the different electrical ones if you're taking electrical), and then decide. However, I would not suggest taking anything other than what you had planned on taking. First of all, looking at the other sections wastes valuable time, and second, you cannot prepare for one section and then take another and do as well in it.

4. It says not to bring your own pencil; they're going to supply us with pencils?

Yes.

5. It says I can't have my cell phone. Even if it's off?

The proctors will hold your cell phones for you. It's easier if you just leave it in your car though.

6. What's the timeline, really?

They begin letting people in at about 7:15. They want you all seated, then do a check in and check calculators, etc. The test will start sometime between 7:45 and 8:10 it will run for 4 hours (12:10). Then they collect the booklets and dismiss for lunch (12:20). They give you a little more than an hour for lunch, but you should just bring your lunch. You leave all your stuff at your desk, and just take your lunch. You come back (1:20) and they re-check everyone in. The afternoon session starts at about 1:45 and runs for 4 hours (5:45). They then have to collect the booklets and dismiss (6:15). This can vary in either direction by 15-20 minutes.

7. What do I bring?

Bring all the references they tell you to that you can find. Beg, buy, borrow...I cannot officially advocate stealing...But there are things you will need just to look something up. Add to that, the Lindeburg book, the practice problems, the sample exams, anything you have that you used to study. AND a dictionary, even a normal dictionary will help, but a lot of people say an engineering dictionary is best. If you have any questions, you can email me, or post them as a comment.

Finished

2008-03-25T08:58:00.000-07:00

I think this blog has helped me as far as it will. It gave me daily goals to achieve and I did them. Up until I started looking at sample exams. So you can continue to follow the schedule, I don't have any more to write about. I don't think.

I will probably post after the test to say how I feel about it.

I will probably post to tell you my grade.

If I have to revive this blog for the October Exam, I will.

Construction

2008-03-24T06:00:00.000-07:00

I just discovered the addition of Construction stuff to the Civil PE exam. I have not touched Construction stuff. So I'm going to go back and do Chapter 81 - Project Management - 6 problems and skim through Chapter 82 - Construciton and Jobsite safety.

I have begun trying to procure all the necessary standards.

I did start on the Lindebure sample exam.

Structural Analysis - Day 2 - Answers

2008-03-20T18:13:00.000-07:00

I marked these pages:
3 moment equation - Section 7 - Page 46-5

Today's Answers:

Structural Analysis - Day 2 - Questions

2008-03-20T14:12:00.000-07:00

Structural Analysis - Day 2

2008-03-20T02:12:00.000-07:00

Chapter 46 - Structural Analysis I - 18 Problems

Structural Analysis - Day 1 - Answers

2008-03-19T14:11:00.000-07:00

I marked these pages:

Thermal Expansion, (alpha) - Table 44.2 - Page 44-4

Today's answers:

Structural Analysis - Day 1 - Questions

2008-03-19T10:00:00.000-07:00

1. A straight beam 150 ft long is installed when the temperature is 40°F. It is support so that only 0.5 in expansion is allowed. Lateral support prevents buckling. If the temperature increases to 100°F – Find the compressive stress in the member.

2. A cantilever beam is 7 ft long. The cross section is 5.5 in wide and 4.5 in deep. E = 1.5x10^6 psi. There are two concentrated: 150 lbf forces 1 ft from the free end and 100 lbf 2 feet from the free end. Find the tip deflection.

3. A steel truss as shown below has R1 pinned and R2 is a roller. The length to Area ratio for each member is 45 in^(-1) E of steel is 29,000 ksi. Find the vertical deflection where the load is applied.

4. A bimetallic spring is constructed of aluminum with a ¼ in by 2 in cross section bonded on top of a 1/8 in by 2 in steel strip. E of aluminum = 10,000 psi, E of steel is 30,000 psi. Find the equivalent all aluminum centroidal area moment of inertia of the cross section.

Structural Analysis - Day 1

2008-03-19T08:00:00.000-07:00

Chapter 44 - Strength of Materials - 12 Problems

Structural Steel: Compression and Beam-Columns - Answers

2008-03-18T17:58:00.000-07:00

I marked these pages:

K, Effective length factor - Figure 61.2 - Page 61-3

I also marked some of the pages I used in the steel book - because it took so long to find them.

(I tried to condense the answers for the past couple days - but I don't look how they look, so I'm going back to the old way.)

Today's Answers:

Structural Steel: Compression and Beam-Columns - Questions

2008-03-18T13:53:00.000-07:00

1. A 22 ft high column pinned at both ends made from an A36 channel and wide flange as shown. Column is constrained in the x plane at mid height.

a) Find the cross sectional area
b) Centroidal moment of inertia about x-axis
c) Centroidal moment of inertia about y-axis
d) Radius of gyration about x- axis
e) Radius of gyration about y- axis
f) Slenderness ratio of column in x-axis
g) Slenderness ratio of column in y-axis
h) Maxmimum slenderness ratio
i) Allowable compressive stress
j) Allowable axial compressive load

2. Select A36 columns of the frame shown. Assume to be braced in plane perpendicular to frame. Girders are W12x106

3. Truss shown is constructed of a variety of members, all of which are assumed to be pin ended. Determine whether all members are adequate, specify replacements with same nominal depth. Assume top chord is braced laterally at every joint.

Top and Bottom Chords W8x24 (A36)
Diagonal bracing L3.5 x 3.5 x 3/8 (pair)
Vertical members L 4 x 4 x 3/8 (pair)

4. A tall column is as shown. The strut is the lateral bracing. No compression flange support. Select an economical A36 W18 section based on stress and deflection.

Structural Steel: Compression and Beam-Columns

2008-03-18T13:24:00.000-07:00

Structural Steel: Compression and Beam-Columns

Chapter 61 Structural Steel: Compression members - 5 problems
Chapter 62 Structural Steel: Beam-Columns - 4 problems

Structural Steel: Beams - Answers

2008-03-17T13:20:00.000-07:00

I didn't mark any pages for this. I had already marked the pages of the beam diagrams in my steel manual.

Today's answers:

Structural Steel: Beams - Questions

2008-03-17T09:30:00.000-07:00

1. A 24 foot steel beam of A36 steel is simply supported on its left end and 7 feet from its right end. A load of 3200 lbf/ft is uniformly distributed over its entire length. Lateral support at reactions only. The beams dead weight is 60 lbf/ft. Choose a W shape. Do not check shear.

2. Select an A36 W shape with lateral support every 6 ft to span 22 ft And carry a uniform load of 1.2 kips/ft Including a 50 lbf/ft dead load. Max deflection is L/240

3. A 60 ft steel beam carries a dead load of 1.5 kip/ft, excluding self weight, over entire span. Supports are at 0 ft (A), 30 ft (C), 55 ft(D) and a hinge is at 25 ft(B).
a) Find the reaction at 0 ft (A)
b) Find the Reaction at 30 ft (C)
c) Find the reaction at 55 ft (D)
d) Find the absolute minimum Shear value
e) Find the location of the maximum shear
f) Find the maximum Moment
g) Find the location of the maximum moment
h) Use unbraced length of 30 ft, find the best W18 section of A36 for moment capacity
i) Find the actual shear stress for the beam chosen
j) Using 42 ksi steel, for the same shape chosen, find the unbraced length that permits the development of 0.66Fy bending stress

Structural Steel: Beams

2008-03-17T09:29:00.000-07:00

Structural Steel: Beams

Lindeburg Chapter 59 - 6 problems

Mixing Concrete and Concrete Beams - Day 2 - Answers

2008-03-13T14:40:00.000-07:00

I marked these pages:

Rebar - Appedix 48.A - Page 48-5

Today's Answers:

Mixing Concrete and Concrete Beams - Day 2 - Questions

2008-03-13T08:39:00.000-07:00

1. A simply supported reinforced concrete beam spans 22 ft as shown. The beam is subjected to a uniform service dead load equal to 2.1 kips/ft (exclusive of beam weight) and to a uniform service live load of 2.5 kips/ft. f’c = 3000 lbf/in^2 and fy = 40,000 lbf/in^2. The depth of reinforcing is 25 in

a) Find the factored uniform load.
b) Find the tension steel required for the maximum moment
c) Find the maximum area of tension steel permitted
d) Find the minimum area of tension steel permitted
e) Find the maximum uniform factored load that the beam can sustain if no compression steel is used
f) Find the spacing of No. 3 U-shaped stirrups at the location where the shear is maximum
g) Find the total length of the beam where no shear reinforcement is required
h) Find the maximum uniform factored load that the beam can be designed for.
i) If live load is reduced to 50% of maximum, what is the new service moment
j) Find the cracking moment

2. A reinforced concrete T beam with a 25 ft span and a 24 in effective width in a floor slab system is fixed at both ends and is reinforced as shown. f’c=3000lbf/in^2 and fy=60,000lbf/in^2
a) Find the design moment capacity in the positive moment region
b) At capacity – find the stress in the compression steel in the negative moment region
c) Find the gross moment of inertia
d) Find the cracked moment of inertia in the positive moment region
e) Find the cracking moment in the positive moment region
f) Find the cracking moment in the negative moment region
g) If a uniformly distributed service load of 3.5 kips/ft acts on the beam. Using refined equation for steel stress, find the stress in the tension steel in the positive moment region.
h) Find the maximum spacing of the tension steel bars based on cracking
i) Find the maximum uniform factored load that the beam can sustain as controlled by shear reinforcement
j) Find the maximum uniform factored load that the beam can sustain as governed by the flexural capacity.

3. A beam must withstand and ultimate factored moment of 410,000 ft-lbf. f’c=4000 psi and fy=40,000psi. No 3 stirrups will be used. (Do not design shear reinforcement, check for cracking or deflections)

a) Determine beam width and depth
b) Determine required steel area
c) How many layers of steel are needed?
d) what is the overall beam depth?

4. The simply supported tension-reinforced beam shown carries 2 identical sets of point loads and a set of uniform loadings. The beam has a width of 18 in. f’c= 3000psi, and fy=60,000psi.
a) Find the ultimate moment
b) Find minimum reinforcement depth
c) Detail reinforcing steel
d) Use No 3 bars to design shear reinforcing

Mixing Concrete and Concrete Beams - Day 2

2008-03-13T07:38:00.000-07:00

Chapter 50 in Lindeburg.

Chapter 50 - Reinforced Concrete: Beams - 11 Problems

Mixing Concrete and Concrete Beams - Day 1 - Answers

2008-03-12T14:00:00.000-07:00

I marked these pages:

Concrete strength - Section 11 - Page 48-5

Today's Answers:

Mixing Concrete and Concrete Beams - Day 1 - Questions

2008-03-12T08:37:00.000-07:00

1. The 8 in by 8 in concrete beam section shown below was tested in a third point loading apparatus. The failure occurred outside the middle third as shown under a maximum total load of 5000lbf. The beam was normal weight concrete with compressive strength of 5000psi. Neglect the beam’s self weight.

a) Find the maximum shear force.
b) Find the maximum bending moment
c) Find the shear force within the middle third.
d) Find the shape of the moment within the middle third
e) Find the modulus of rupture
f) If the fracture had happened in the middle third, find the modulus of rupture.
g) Use the ACI empirical equation to find the modulus of rupture.
h) If the beam is made of lightweight concrete, what is the modulus of rupture?

2. A normal weight concrete structure tested at 28 days yields the following:
a) An 8 in by 10 in concrete cylinder failed in axial compression at 110,000 lbf. Find the ultimate compressive strength.
b) An 8 in by 10 in concrete cylinder resisted a transverse force of 50,000 lbf in a split cylinder test, find the tensile strength.
c) An 8 in square unreinforced beam section resisted a force of 5500 lbs on a 24 in span length. A third point loading test was used and the fracture occurred within the middle third. Find the modulus of rupture.
d) Find the ratio of the modulus of rupture to the compressive strength
e) Find the ratio of the split tensile strength to the compressive strength
f) Given a compressive strength of 3800 lbf/in^2 find the modulus of rupture.
g) Axial strain is 0.0016 in/in and lateral strain is 0.00028 in/in. Find Poission’s ratio.

3. A trial batch of concrete is needed according to the following requirements:

# of sacks of cement per yd^3 of concrete = 8
Entrained air – 5%
Total water-cement ratio = 0.55
Cement specific gravity = 3.20

For economical reasons, 2 sizes of coarse aggregate were used. The aggregates are as follows:
SG Moisture % by volume
Fine aggregate 2.55 5% excess 35%
¾ in coarse 2.60 2% excess 17%
1.0 in coarse 2.57 3% deficit 48%

a) find the weight of cement needed for 2 yd^3 of concrete
b) find the volume of cement needed for 2 yd^3 of concrete
c) find the weight of water needed for 2 yd^3 of concrete
d) find the volume of water needed for 2 yd^3 of concrete
e) The absolute volume of fine aggregate in 2 yd^3
f) The SSD weight of fine aggregate in 2 yd^3
g) The absolute volume of ¾ in aggregate in 2 yd^3
h) The absolute volume of 1.0 in aggregate in 2 yd^3
i) The SSD weight of ¾ in aggregate in 2 yd^3
j) The SSD weight of 1.0 in aggregate in 2 yd^3

Mixing Concrete and Concrete Beams - Day 1

2008-03-12T07:35:00.000-07:00

Chapters 48 and 49 in Lindeburg

Chapter 48 - Properties of Concrete and Reinforcing Steel - 5 Problems

Chpater 49 - Concrete Proportioning, Mixing, and Placing - 3 Problems

Traffic and Accident Analysis - Answers

2008-03-11T14:00:00.000-07:00

I marked these pages:

Headway, Spacing, Volume - Section 10 - Page 74-6

Warrants for signal - Section 16 - Page 74-14

I also downloaded some info from the HCM 2000 - in the form of class notes regarding the designs for 2 lane highways and multiland highways - I didn't feel like the info in the book was enough, especially since the answers to the questions kept referencing HCM.

Today's Answers:

Traffic and Accident Analysis - Questions

2008-03-11T08:32:00.000-07:00

I am studying the material in Chapter 74, but the questions require the use of HCM, which I do not currently have, so I am not able to post questions, since I’m am unsure I will be able to answer them.

For Chapter 75 though – I present these 2:

1. Two cars are moving at 50 mph in the same directions in the same lane. The cars are separated by 20 ft per 10 mph. The coefficient of friction (skidding) is 0.65. The reaction time is assumed to be 0.4 sec.
a) If the lead car hits a parked car, what is the speed of the second car when it hits the first car?
b) If the lead car hits a parked car and comes to an abrupt halt, at what speed does the rule of 1 car length (20 ft) per 10 mph of speed become unsafe?
c) At 60 mph what should the rule actually be?

2. Two vehicles collide head on while traveling a curve with a 4% grade. Vehicle A skidded 200 feet downhill before colliding with vehicle B. Vehcile B skidded 150 ft. The police report estimates both car traveling at 30 mph prior to the collision. Assume a coefficient of friction of 0.5.
a) What was the speed of vehicle A prior to hitting the brakes?
b) What was the speed of vehicle B prior to hitting the brakes?
c) Which assumption produces the greatest possible error?

Traffic and Accident Analysis

2008-03-11T07:30:00.000-07:00

Chapters 74 and 75 in Lindeburg

Chapter 74 - Roads and Highways : Capacity Analysis - 6 Problems

Chapter 75 - Vehicle Dynamics and Accident Analysis - 4 Problems

Highway Curves - Answers

2008-03-10T14:00:00.000-07:00

I marked these pages:

Stopping Sight Distance - Table 79.2 - Page 79-10

Today's Answers:

Highway Curves - Questions

2008-03-10T09:28:00.000-07:00

1. Use the following diagram:

a) At what station is the low point located?
b) At what elevation is the low point?
c) At what elevation is the sta 21+75.05
d) What is the highest design speed for the curve?
e) What is the rate of grade change per station?
f) If 18 ft of clearance is required, what is the lowest elevation that the bottom of an overhead bredige deck may have at sta 22+75

2. The grades on a vertical curve intersect at station 110+00 and elevation 352 ft. A drain grating exists at sta 110+00 at elevation 360.25 ft

a) Given a curve length of 1800 ft, what is the elevation of BVC?
b) Given a curve length of 1800 ft, what is the elevation of sta 111+40?
c) Given a curve length of 1800 ft, what is the elevation of the low point?
d) Given a curve length of 1800 ft, what is the station of BVC?
e) Given a curve length of 1800 ft, what is the elevation of EVC?

3.
The tangent of the horizontal curve shown is relocated 12 ft west of its original position. The PC remains the same.
a) What is the original curve radius?
b) What is the new curve radius?

Highway Curves

2008-03-10T08:27:00.000-07:00

Chapter 79 in Lindeburg

Chapter 79 - Horizontal, Compound, Vertical, and Spiral Curves - 15 Problems

Surveying - Answers

2008-03-06T14:00:00.000-08:00

I marked these pages:

Errors (Survey) - Section 1 ---> - Page 78-1

Elevation corrections - Section 18 - Page 78-9

Today's Answers:

Surveying - Questions

2008-03-06T08:25:00.000-08:00

1.
Errors
Four level circuits were run over four different routes. The elevation and error for each circuit is listed below. What is the most probably value of the benchmark’s elevation?

Route 1: 745.07 ± 0.02
Route 2: 745.22 ± 0.03
Route 3: 745.40 ± 0.08
Route 4: 745.16 ± 0.04

2.
Leveling
A level is placed where the height of the instrument above datum is 294.45 ft. The rod is held on a point 4000 ft away. And a reading of 4.65 ft is recorded.
a) Find the effect of the earth’s curvature on the rod reading
b) Find the effect of the atmospheric refraction on the rod reading.

3.
A 5 leg closed traverse is taped and scoped in the field, but obstructions make it impossible to collect all the readings. It is known that the general direction of EA is east west. Complete the field notes:

Leg north azimuth distance
AB 106.22° 1081.3
BC 195.32° 1589.5
CD 247.12° 1293.7
DE 332.37° ______
EA ______° 1081.3

4.
Photogrammetry
A camera with a focal length of 5 inches and a size of 10 in by 10 in is used to photograph an area from an altitude of 4500 ft above sea level.
a) If the average elevation is 600 ft, what is the average scale of the photo?
b) What is the ground area covered by a single photograph?
c) If overlap and sidelap are 50% and 30% respectively, what is the ground spacing between exposures?
d) same as c) what is the ground spacing between flight lines?
e) if the aircraft is moving at 325 mph ground speed, what is the time interval to the nearest 0.1 sec between exposures?
f) two points at elevation 650 ft appear 90 mm apart on the photo, what is the ground distance?
g) what elevation should a plane be flown to get an average scale of 1:10,000 if the elevation is 1100-1300 ft above sea level.

Surveying

2008-03-06T07:24:00.000-08:00

Chapter 78 in Lindeburg

Plane Surveying - Chapter 78 - 9 Problems

Retaining Walls and Deep Foundations - Day 2 - Answers

2008-03-05T12:00:00.000-08:00

I marked these pages:

Piles - Section 3 - Page 38-3

Today's answers:

Retaining Walls and Deep Foundations - Day 2 - Questions

2008-03-05T09:13:00.000-08:00

1. A 10.75 in diameter steel pipe is driven 70 ft into stiff insensitive clay. The clay has an un-drained shear strength of 1250 lbf/ft^2. The clay's specific weight is 120 lbf/ft^3. Water table at ground surface. Entire pile length is effective.
a) Find the end bearing capacity.
b) Find the friction capacity.
c) Find the allowable bearing capacity.

2. Test show that a single pile by itself would have an uplift capacity of 140 tons. And a compressive capacity of 600 tons. 36 piles are installed on a grid with a spacing of 3.5 ft. The pile group is capped and connected at the top by a thick steel-reinforced concrete slab adding it's own axial load of 600 tons. What is the maximum moment that the pile group can take in the x and y directions assuming axial load is applied to permit the moment.

3. A 25 ft deep, 35 ft square excavation in sand is being designed. The sand is dewatered before excavation. The angle of internal friction is 40° and the specific weight of the sand is 120 lbf/ft^3. Bracing is horizontal lagging, supported by 8 in soldier piles separated horizontally by 7 ft.
a) What is the shape of the pressure diagram on the lagging?
b) What is the bending moment on the lagging?

Retaining Walls and Deep Foundations - Day 2

2008-03-05T07:11:00.000-08:00

Chapters 38 and 39 in Lindeburg.

These are the chapters in the practice problems book:

Chapter 38 - Piles and Deep Foundations - 2 problems

Chapter 39 - Temporary Excavations - 2 problems

Confession

2008-03-05T06:40:00.000-08:00

I am ahead of schedule. I created posts for the days of the schedule. I am currently about half way through Thursday's stuff. I'm going to go ahead and post it when I finish it - but I'm leaving the dates where they are, because I may get back on schedule at some point.

Retaining Walls - Answers

2008-03-04T09:06:00.000-08:00

I marked these pages:

Retaining Wall Analysis - Section 11 - Page 37-6

And today's answer's are:

Retaining Walls - Questions

2008-03-04T06:35:00.000-08:00

1. A retaining wall is designed for free-draining granular backfill. After several years of operation the weep holes become plugged and the water table rises to within 8 feet of the top of the wall.

a) What is the resultant force for the drained case?

b) What is the point of application of the drained case?

c) What is the resultant force for the plugged case?

d) What is the point of application of the resultant force for the plugged case?

2. Retaining Wall Design:
A reinforced concrete retaining wall is used to support a 15 ft cut in sandy soil. The backfill is level, but a surcharge of 450 lbf/ft^2 is present for a considerable distance behind the wall. Factor of safety of 1.4 against sliding and overturning are required. Customary and reasonable assumptions can be made. Passive pressure is disregarded. The need for a key must be established.

Soil drained specific weight = 125 lbf/ft^3
Angle of internal friction = 35°
Coefficient of friction against concrete = 0.45
Allowable soil pressure = 4800 lbf/ft^2
Frost line = 3.5 ft below grade

a) What is the minimum stem height?

For b-j, assume a base length B of 12 ft and a base thickness d = 2 ft. A stem thickness at base of 2 ft. And a stem thickness at top of 1.5 ft. A stem height above base of 19 ft. And a heel extension (past back of stem) = 7 ft.

b) What thickness of backfill is equivalent to the surcharge?
c) What is the horizontal reaction due to the surcharge?
d) What is the active soil resultant?
e) What is the total overturning moment, taken about the toe, per foot of wall?
f) What is the factor of safety against overturning?
g) What is the maximum vertical pressure at the toe?
h) What is the minimum vertical pressure at the heel?
i) What is the factor of safety against sliding without a key?
j) What is the factor of safety against sliding if a key of 2 ft wide and 1 ft deep is used?

Retaining Walls and Deep Foundations - Day 1

2008-03-04T06:33:00.000-08:00

Chapter 37 in Lindeburg.

These are the chapters in the practice problems book:
Chapter 37 – Rigid Retaining Walls - 3 problems

Soils, Foundations, and Settlements - Part 2 - Answers

2008-03-03T12:32:00.000-08:00

I marked these pages:

Bearing Capacity - Sections 4 (and on) - Starts of Page 36-3

Taylor Slope Stability - Figure 40.6 - Page 40-7

And today's answer's are:

Soils, Foundations, and Settlements - Part 2 - Questions

2008-03-03T10:21:00.000-08:00

1. A mat foundation is used to support a building with dimensions 75 ft by 45 ft and a total load of 5400 tons. The mat is at a depth of 7.5 ft below ground surface. The soil beneath the mat has a density of 115 lbf/ft^3 and an average SPT N-value of 18.
a) Find the allowable bearing capacity.
b) Find the factor of safety against bearing capacity.

2. A 2.5 m by 2.5 m square spread footing is designed to support an axial column load of 650 kN and a moment of 155 kN*m. The footing is place 1m into a sandy soil with a density of 2050 kg/m^3 and an angle of internal friction of 30°.
a) Find the eccentricity of the resultant load.
b) Find the equivalent width that should be used for the footing design.
c) Use the Meyerhoff theory, what is the value of the bearing capacity factor Ny to be used in calculating bearing capacity?
d) Use the Meyerhoff theory, what is the value of the bearing capacity factor Nq to be used in calculating bearing capacity?
e) Use the Meyerhoff theory, what is the value of the shape factor for Ny to be used in calculating bearing capacity?
f) What is the value of the net bearing capacity?
g) What is the value of the allowable bearing capacity?
h) What is the total allowable load?
i) What is the maximum soil pressure on the bottom of the footing?
j) What is the factor of safety against bearing capacity?

3. A 12 ft x 12 ft footing exerts a pressure of 4000 lbf/ft^2 on the soil below it. What is the increase in vertical soil stress 8 ft below and 6 feet from center of the footing?

4. A 2:1 (horizontal :vertical) sloped cut is made in homogeneous saturated clay. The clay's specific weight is 110 lbf/ft^3 and ultimate shear strength is 1050 lbf/ft^2. The cut is 45 ft deep. The clay extends 12 ft below the toe of the cut to the rock layer. What is the cohesive factor of safety of this cut?

Soils, Foundations, and Settlements - Part 2

2008-03-03T10:05:00.000-08:00

Chapters 36 and 40 in Lindeburg.

These are the chapters in the practice problems book:
Chapter 36 – Shallow Foundations - 4 problems
Chapter 40 – Special Soil Topics - 9 problems

Soils, Foundations, and Settlements - Answers

2008-02-28T12:29:00.000-08:00

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

2008-02-28T08:05:00.000-08:00

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

2008-02-28T07:55:00.000-08:00

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

2008-02-27T17:24:00.000-08:00

I marked the following pages:

Relative Oxidation Powers - Table 34.1 - Page 34-4

And today's answers are:

Pollution and the Environment - Questions

2008-02-27T08:05:00.000-08:00

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

2008-02-27T07:55:00.000-08:00

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

2008-02-26T12:19:00.000-08:00

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

2008-02-26T08:00:00.000-08:00

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

2008-02-26T07:55:00.000-08:00

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

2008-02-25T17:41:00.000-08:00

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

2008-02-25T08:00:00.000-08:00

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

2008-02-25T07:55:00.000-08:00

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

2008-02-21T11:46:00.000-08:00

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

2008-02-21T08:03:00.000-08:00

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

2008-02-21T07:52:00.000-08:00

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

2008-02-20T14:39:00.000-08:00

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

2008-02-20T10:00:00.000-08:00

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

2008-02-20T07:50:00.000-08:00

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

2008-02-19T14:36:00.001-08:00

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

2008-02-19T11:16:00.000-08:00

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

2008-02-19T07:35:00.000-08:00

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

2008-02-19T07:26:00.000-08:00

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?

2008-02-19T06:06:00.000-08:00

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.