09/09/2017

A Summary of the “Structural Depth Practice Exams for the Civil PE Exam, Third Edition”

In this post, I will provide a brief description of each question that is found in the “Structural Depth Practice Exams for the Civil PE Exam”, Third Edition. This book is published by PPI and contains two full length 40-problem, multiple-choice exams covering the structural depth portion of the Civil PE Exam. I will first cover the 40 questions in the first practice PE Exam, and then cover the 40 questions in the second practice PE Exam.

 

 

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Exam 1

 

PE Practice Exam Question 1

In the first question, a simply supported pin-connected plane truss is subjected to a single vertical load and single lateral load applied to different truss joints. We are asked to find the number of zero-force members.

 

PE Practice Exam Question 2

In the second question, a railroad car is supported by two simply supported bridge girders. We are asked to find the vertical reaction at the right support of either girder.

 

PE Practice Exam Question 3

In the third question, a propped cantilever beam is loaded with a concentrated vertical load at a certain distance away from the fixed support. We are asked how to decrease the vertical reaction at the fixed support.

 

PE Practice Exam Question 4

In the fourth question, a four-span continuous beam is subjected to a uniform load. We are asked to compute the maximum positive and negative bending moments for the beam.

 

PE Practice Exam Question 5

In the fifth question, a truck is supported by a simply-supported steel girder. We are asked to compute the maximum shear on the steel girder.

 

PE Practice Exam Question 6

The sixth questions asks about the required diameter of weepholes in exterior veneer wall systems according to ACI 530.

 

PE Practice Exam Question 7

The seventh question focuses on the acceptable methods of assessing stability requirements of a steel building based on the provisions in the AISC Steel Construction Manual.

 

PE Practice Exam Question 8

The eighth question asks the purpose of the Ylinen equation, which is found in the National Design Specification for Wood Construction.

 

PE Practice Exam Question 9

The ninth question is concerned with the requirements for vehicular live loading on bridge roadways in accordance with AASHTO LRFD Bridge Design Specifications (AASHTO).

 

PE Practice Exam Question 10

The tenth question is related to the welding procedure specification for a HSS welded connection per AISC Steel Construction Manual.

 

PE Practice Exam Question 11

The eleventh question asks about the maximum moisture content of lumber based on a grade stamp that was placed on a sample of machine evaluated lumber.

 

PE Practice Exam Question 12

In the twelfth question, a reinforced concrete slab is supported by two parabolic steel cables. We are given the allowable tension in the steel cables and are asked to find the the total uniform unfactored load on the slab that the cables can support.

 

PE Practice Exam Question 13

In the thirteenth question, a reinforced concrete flat plate slab is supported by columns. We are asked to calculate the tributary area for two-way shear for the interior column per ACI Code 318-11.

 

PE Practice Exam Question 14

In the fourteenth question, a cross section of a singly reinforced concrete rectangular beam is shown. We are asked to compute the distance from the centroid of the reinforcement to the bottom edge of the cross-section using ACI Code 318-11.

 

PE Practice Exam Question 15

In the fifteenth question, a structure with 3 buildings is presented. We are asked to find the total unfactored load due to uniform snow loading for the middle building.

 

PE Practice Exam Question 16

In the sixteenth question, a partially grouted reinforced masonry wall consisting of 8″ CMU blocks experiences only axial compression. We are asked to find allowable axial capacity of the wall using the the masonry code, ACI 530-11.

 

PE Practice Exam Question 17

In the seventeenth question, a mezzanine floor slab is supported by a column and beam assembly, which are spaced at regular intervals along the length of the building. We need to determine the axial load that is transferred from each beam to column.

 

PE Practice Exam Question 18

The eighteenth question deals with construction joints and when they are most likely to be an essential part of the structural design.

 

PE Practice Exam Question 19

The nineteenth question asks us about the maximum water-cement ratio allowed for a specific concrete mix per ACI Code 318-11.

 

PE Practice Exam Question 20

The twentieth question asks us about the sound transmission class rating of a precast concrete wall system.

 

PE Practice Exam Question 21

The twenty-first question deals with the tensile strength value of steel plate using the AISC Steel Construction Manual.

 

PE Practice Exam Question 22

The twenty-second question relates to the mortar that may be used in a masonry seismic force resisting system according to ACI 530-11.

 

PE Practice Exam Question 23

In the twenty-third question, a simply supported beam is subjected to a concentrated load and bending couple at different points along the length of the beam. We are asked to determine the general shape of the bending moment diagram.

 

PE Practice Exam Question 24

In the twenty-fourth question, a steel beam column is subjected to concentrated transverse load coupled with a concentric axial load. We are asked to find the normal stress acting on the lower flange of beam-column at midspan.

 

PE Practice Exam Question 25

In the twenty-fifth question, the cross-section of a concrete filled HSS steel column is shown. We are asked to find the nominal axial capacity of the column using the AISC Steel Construction Manual.

 

PE Practice Exam Question 26

In the twenty-sixth question, a one-way reinforced concrete cantilever slab supports a balcony. We are asked to find the minimum required thickness of the slab based on ACI Code 318-11.

 

PE Practice Exam Question 27

In the twenty-seventh question, we are asked to find the maximum torque  a hollow shaft can sustain given a governing angle of twist.

 

PE Practice Exam Question 28

In the twenty-eighth question, a flexible diaphragm is supported by three reinforced masonry shear walls and is subjected to a vertical uniform wind load. We are asked to determine the shape of the shear force diagram of the diaphragm.

 

PE Practice Exam Question 29

The twenty-ninth question deals with the location of prestressing for a composite bridge per AASHTO LRFD Bridge Design Specification.

 

PE Practice Exam Question 30

The thirtieth question is concerned with how to calculate the ultimate factored shear force for reinforced and prestressed concrete members with regards to location from the face of the support.

 

PE Practice Exam Question 31

The thirty-first question deals with the axial load capacity of square, short, reinforced concrete columns.

 

PE Practice Exam Question 32

The thirty-second question focuses on the factors that led to the collapse of the walkway system in the Kansas City Hyatt Regency Hotel. 

 

PE Practice Exam Question 33

In the thirty-third question, an overhanging simply supported steel truss is shown. We are asked to design the most economical gross cross-section of the truss top chord using the ASD or LRFD approach based on the given load cases.

 

PE Practice Exam Question 34

In the thirty-fourth question, a bolted steel connection is subjected to an eccentric inclined loading. We are asked to compute the capacity of the connection based only on bolt shear failure using the ASD or LRFD approach.

 

PE Practice Exam Question 35

In the thirty-fifth question, a load bearing basement retaining wall supports a floor joist on top and is supported by a concrete footing. We are asked to identify the steel reinforcement configuration that best suits this wall given that the top and bottom wall connections are not moment-resisting.

 

PE Practice Exam Question 36

The thirty-sixth question deals with the characteristics of expansive soil according to the International Building Code (IBC).

 

PE Practice Exam Question 37

In the thirty-seventh question, a concrete pile cap is supported by five rows of micropiles and is subjected to an overturning moment. Assuming that the micropiles can only resist axial loads, we are asked to find the load on each micropile due to the overturning bending moment.

 

PE Practice Exam Question 38

In the thirty-eighth question, a strap footing supports axially concentric loaded columns on each side of the footing. We are asked to determine the maximum soil pressure beneath one of the footings.

 

PE Practice Exam Question 39

The thirty-ninth question deals with requirements of personal protective  and lifesaving equipment specified  by OSHA. 

 

PE Practice Exam Question 40

The fortieth question is concerned with the negative scenarios that could occur during the installation of drilled piers.

09/07/2017

Calculating the Seismic Design Force and Seismic Base Shear for a Building Using the Simplified Analysis Procedure

In this post, I will go over the second seismic design example in our seismic design of structures course covering the calculation of seismic forces. The goal of this structural seismic design example is to calculate the seismic design force and seismic base shear for a reinforced concrete building structure. We will use the simplified analysis procedure.

 

Problem Description

 

The problem statement states,

 

Compute the seismic design force, seismic shear force, and check the lateral deformation for a structure given the following information:

 

Building Material – Reinforced Concrete
Nature of Building Occupancy – Minor Storage Facility
Basic Seismic Force Resisting System – Ordinary Reinforced Shear Wall System
Number of Stories – 2
Height of Each Floor – 12 ft
Weight of Each Floor – 40 Kips
Seismic Design Category – D
Soil Type – Soft Rock
Design Spectral Response Acceleration Coefficient for Short Period – 1.35g

 

Step 1 – Identify Seismic Risk Category

 

The first step is to identify the risk category of the reinforced concrete building. The risk category is based on Section 1604.5 of the International Building Code (IBC) 2012. The title of Table 1604.5 is “Risk Category of Buildings and Other Structures”. According to this table, the risk category for minor storage facilities is 1.

 

Step 2 – Identify Site Classification

 

The second step is to identify the site classification of our building based on the soil type. The problem statement tells us that the soil type is soft rock. Using Table 20.3-1 of ASCE 7-10, we see that a site with soft rock is considered to be class C.

 

Step 3 – Check if the Simplified Analysis Procedure is Applicable

 

To simplify our analysis, we can use what’s known as the simplified analysis procedure as outlined in Section 12.14 of ASCE 7-10. In order to use this approach, we must ensure that our structure satisfies the following conditions:

 

The risk classification of the structure based on the nature of occupancy can only be risk category 1 or 2.

The site class cannot be class E or F.

The maximum height of the structure above grade cannot be greater than 3 stories.

The seismic force resisting system that is utilized must either be a bearing wall system or building fame system.

The structure should have a minimum of two lines of lateral resistance in each of two major axis directions.

 

Our structure has a risk category of 1, is less than 3 stories high, and utilizes a bearing wall system to resist the seismic force. Therefore, we may use the simplified analysis procedure as outlined in ASCE 7-10.

 

Step 4 – Identify Response Modification Factor

 

The fourth step is to choose the appropriate response modification factor, R, using Table 12.14-1 of ASCE 7-10. Under the bearing wall system section, we find that the response modification factor is equal to 4 for a ordinary reinforced concrete shear wall.

 

Step 5 – Compute Effective Seismic Weight

 

The fifth step is to compute the effective seismic weight of the structural building. For this example, it is equal to the summation of the floor weights for the whole building.

 

Step 6 – Compute Seismic Base Shear

 

The sixth step is determine the seismic base shear, V. Per Equation 12.14-11 of ASCE 7-10, it is equal to the design spectral response acceleration coefficient for short period times the effective seismic weight times “F” divided by the response modification factor. For a two-story building, “F” can be taken as 1.1 per Section 12.14.8.1 of ASCE 7-10.

 

Step 7 – Calculate Seismic Lateral Force for Each Level, FX

 

The seventh step is to calculate the lateral force, Fx, for each level. Per Equation 12.14-12 of ASCE 7-10, it is equal to the seismic base shear times the weight of the given level divided by the total effective seismic weight.

 

Step 8 – Calculate Seismic Story Shear, VX

 

The eighth step is to compute seismic story shear, Vx, per Equation 12.8-13 of ASCE 7-10.

 

Step 9 – Calculate Overturning Moment, MX

 

The ninth step is to determine the overturning moment, Mx, at each level.

Step 10 – Calculate Seismic Lateral Story Drift

 

The tenth step is to determine the seismic lateral story drift. Since we are using the simplified analysis procedure, we are allowed to take the seismic lateral story drift as 1% of the the story height per Section 12.14.8.5.

 

Step 11 – Check Seismic Lateral Story Drift

 

The eleventh step is to check the seismic lateral story drift. The allowable story drift can be found from Table 12.12-1 of ASCE 7-10. The allowable story drift should be greater than or equal to the design story drifts for each floor level.

08/30/2017

Step-by-Step Analysis of a Steel Pipe Pile Foundation Subjected to Axial, Shear, and Bending Loads

In this post, I will go over the second example in our foundation design course covering pile foundations. The goal of this foundation design example is to analyze and asses the structural integrity of a steel, pipe, pile foundation that is subjected to axial, shear, and bending loads.

 

Problem Description

 

The engineering problem statement states,

 

A large sign is to be supported on a single steel pipe pile. Asses the structural integrity of the pile given the following information:

Outside Diameter of Steel Pile – 400 mm
Wall Thickness of Steel Pile – 10 mm
Yield Strength of Steel Pile – 36 ksi
Axial Downward Load Acting on Pile – 50 kN
Shear Load Acting on Pile – 25 kN
Bending Moment Acting on Pile – 95 kN-m

 

 

 Step 1 – Calculate the Inside Diameter of the Steel Pipe Pile Foundation

 

The first step is to calculate the inside diameter of the steel pipe pile foundation. It is equal to the outside diameter minus two times the wall thickness,

 

Step 2 – Calculate the Cross-Sectional Area of the Steel Pipe Pile Foundation

 

The second step is to compute the cross-sectional steel area of the steel pipe pile foundation. It is equal to pi times the pile foundation outside diameter squared minus the inside diameter squared divided by four.

 

Step 3 – Calculate the Pile Section Modulus of the Steel Pipe Pile Foundation

 

The third step is to compute the pile foundation section modulus. It is equal to pi times the pile foundation outside diameter to the fourth power minus the inside diameter to the fourth power divided by thirty two times the outside diameter.

 

Step 4 – Calculate the Axial Stress of the Steel Pipe Pile Foundation

 

The fourth step is to determine the axial stress of the steel pipe pile foundation. The axial stress is equal to the axial load divided by the cross-sectional steel area.

 

Step 5 – Calculate the Bending Stress of the Steel Pipe Pile Foundation

 

The fifth step is to calculate the bending stress of the steel pipe pile foundation. The bending stress is equal to the bending moment divided by the pile foundation section modulus.

 

Step 6 – Calculate the Allowable Axial and Flexural Stress

 

The sixth step is to find the allowable axial and flexural stress. For this example, we are assuming that both the allowable axial and flexural stress are equal to 0.35 times the yield strength of the steel pipe pile.

 

 Step 7 – Calculate the Axial Plus Bending Utilization Ratio

 

The seventh step is compute the axial plus bending utilization ratio. The utilization ratio is equal to axial stress divided by the allowable axial stress plus the flexural stress divided by the allowable flexural stress. If the utilization ratio is less than or equal to one, then the pile is adequate for axial and bending load. If the utilization ratio is greater than one, then the pile is not adequate for axial and bending load and must be redesigned.

 

Step 8 – Calculate the Shear Stress

 

The eighth step is to find the shear stress acting on the steel pipe pile foundation. It is equal to two times the shear load divided by the cross-sectional steel area of the pile foundation.

 

Step 9 – Calculate the Allowable Shear Stress

 

The ninth step is to determine the allowable shear stress. For this example, we are assuming that the allowable shear stress is equal to 0.4 times the material yield stress. If the actual shear stress is less than or equal to the allowable shear stress, then the pile is adequate for shear load. If the actual shear stress is greater than the allowable shear stress, then the pile is not adequate for shear load.

 

Step 10 – Final Design Check

 

The last step is to check the pile for axial plus bending load as well as shear. If the axial plus bending ratio is less than or equal to one and the shear stress is less than or equal to the allowable shear stress, then the structural integrity of the steel pipe pile foundation is acceptable. If the axial plus bending ratio is greater than one and / or the shear stress is greater than the allowable shear stress, then the structural integrity of the steel pipe pile foundation is not acceptable. 

08/30/2017

Designing a Structural Frame to Replace a Load Bearing Wall for a Home in Houston, TX

Completion Date:

August 22, 2017

 

Client:

Private Home Owner

 

Project Location:

Hazelhurst Dr, Houston, TX 77043

 

Project Type:

Structural Engineering Design and PE Stamp of Drawing

 

Project Description:

Engineering Examples was hired by the owner of a residential, single-family home located at 10138 Hazelhurst Dr, Houston, TX 77043. The owner wanted to do a complete re-model of the home. Part of the re-model included removing a load-bearing wall between the kitchen and living room and replacing it with a structural frame. The frame consisted of a engineered, glulam beam spanning 20 ft and supported on each end by timber posts. Because the beam was greater than 16 feet in length, the City of Houston required the owner to get a drawing stamped by a registered professional engineer showing the proposed changes.

 

Engineering Examples calculated the loads acting on the proposed beam and column. The beam was checked for shear, bending, and deflection according to NDS 2012. The column was checked for compression parallel to the grain per NDS 2012. In addition to the beam and columns, we also designed the connection between the existing wood joists and new glulam beam, the connection between the new glulam beam and the new column posts, and the connection between the new column posts and the existing concrete floor. Lastly, we stamped the drawing, so the home owner could get approval from the City of Houston, receive the permit, and begin the re-modeling work.

 

If you need any structural engineering assistance, please contact us at info@engineeringexamples.net.

08/28/2017

Structural Engineering Review and PE Stamp for School Entrance Drawing in Houston, TX

Completion Date:

August 4, 2017

 

Client:

Southwest Graphix

 

Project Location:

Outley Elementary School, 12355 Richmond Avenue, Houston, TX 77082

 

Project Type:

Structural Engineering Review and PE Stamp of Drawing

 

Project Description:

Engineering Examples was hired by Southwest Graphix to review and stamp a drawing for a masonry wall that will be placed at the entrance of Outley Elementary School located at 12355 Richmond Avenue, Houston, TX 77082. The masonry wall primarily consists of 8″ x 8″ x 16″ fully grouted CMU blocks with #5 rebar spaced at 24″ which are completely surrounded by exterior bricks. The entire wall sits on top of a 6″ wide concrete slab. The wall pilasters are supported by 18″ diameter piers which are widened towards the bottom. Below is a brief summary of what Engineering Examples did for this project:

 

We calculated the bearing stress acting at the bottom of the pier and confirmed that it was lower than the allowable bearing pressure provided in the soil report.

 

We calculated the wind load acting on the wall and on each supporting pilaster. From this, we found the bending moment due to wind acting on each pilaster. Next, we computed the resisting moment due to the passive, lateral soil pressure acting along the entire depth of the pier. Then, we confirmed that the bending moment due to wind was less than the resisting moment due to the soil.

 

We designed the longitudinal, pier reinforcement in accordance with the minimum steel area requirements outlined in the soil report.

 

We specified the tie spacing of the pier and pilaster reinforcement based on ACI Code 318-11.

 

To further strengthen the wall against lateral, wind load, we designed a fully grouted, reinforced bond beam that will be placed on the top coarse of the wall.

 

If you need any structural engineering assistance, please contact us at info@engineeringexamples.net.