SIX MINUTE SOLUTIONS FOR CIVIL EXAM

[narayanbaral]

Has anybody tried this problem # 33? I think while calculating concrete deck load, writer did wrong.

the load due to decking in one of the abutment would be 1/2(150*40*15*8/12)=30000 lb or by linear foot method 150*15*8/12*=1500 lb/LF along 40' length=1500*40=60000 lb since question ask for one abutment; divide by 2 =30000 lb (without considering truss load) writer has answer maximum 28000 lb.

Please help me if anybody has gone through this.

Thanks

Narayan

 

[narayanbaral]

I am sorry this is Construction Depth problem.

 

[Chris Raymond]

Yes, I noticed that the weight of the concrete deck is wrong than moved on to another question. Looks like they intended to find the weight per unit foot, but didn't multiply by the width. #76 has missing info and something is strange with the wind load conversion. Might be something wrong with #79 I didn't look into it much. #80 and #95 look to be overly complicated. #97 has a reference to ASCE 7, witch is not one of the NCEES references. Without an errata I would just skip anything that seems strange.

 

[Jayman_PE]

Looks like another well thought out text. Honestly, where is the quality control for these books? We see what happens when career academicians are asked to produce something useful. Lot's of errors.

 

[Lucky1]

Unfortunately this book is in the same vein as the Goswami Practice Exam Book. Between the errors and the overly complicated problems, it's an effort in frustration to work through. While there are some good problems, some are so long that it is physically impossible to get the solution within 6 minutes. Further, many problems could be worded to be clearer and yet have the complicated twist to make you think and look at the details. I'm not sure why it is so difficult to assemble a book with problems similar in format and complexity to the NCEES exam. With some revisions, this could be a valuable study tool for the exam.

 

[pleasepass]

I bought this book also and quite honestly I'm getting tired of spending alotta cash on these faulty texts (the latest CERM construction depth reference manual included)! Afterall, we're looking to work problems and learn a few things along the way and you end up feeling battered, bruised, broke, and lost in the shuffle. I can see a few errors here and there but some of these errors are HUGE and ridiculous! Who's really writing these probems anyway? I find it hard to believe that world-renowned P.E.'s are sitting at their desks working hard to belt these things out and that their competent counterparts are checking their work before final submittal... I know that's what our clients expect when you work for an engineering firm...

 

[Jayman_PE]

I'll put it this way - if I did my work as shoddy as these engineer's write texts I'd be unemployed fast. Time to push back and ask for a refund. If enough of us do that maybe the publishers will get the hint.

thanks,

Jason

 

[Patrick1441 PE]

#32 is another winner. The author states that a wall is 100 feet long with steel spaced 12 in O.C. Somehow he claims 101 bars will fit in there. Apparently there are bars halfway embedded in the concrete at each end. Sadly enough I have seen similar mistakes in plans in the real world that make it all the way to the job site with several P.E. stamps approving them. If nothing else, working problems like this with a critical eye will prepare you for similar twists on the exam. Take nothing for granted; not even the solutions provided!

 

[Patrick1441 PE]

Also, I find it amusing that the author chooses to compute the nominal weight of rebar rather than use the ASTM standards.

 

[treyjay]

#32 is another winner. The author states that a wall is 100 feet long with steel spaced 12 in O.C. Somehow he claims 101 bars will fit in there. Apparently there are bars halfway embedded in the concrete at each end. Sadly enough I have seen similar mistakes in plans in the real world that make it all the way to the job site with several P.E. stamps approving them. If nothing else, working problems like this with a critical eye will prepare you for similar twists on the exam. Take nothing for granted; not even the solutions provided!

maybe I am misunderstanding what you are saying, but if a wall is 100' long and a bar is spaced 12" OC, then there would be 101 bars because you would have to count the first one placed at the start of the wall.

 

[Patrick1441 PE]

In a real reinforced concrete member you would never place a bar on each end. There is a region of concrete cover necessary on each side to protect the steel from corrosion.

 

[Jayman_PE]

Trej and Patrick - you are both correct. It really depends on the particular plan. I've seen situations where the plans call for 101 bars with the end spacings being less than the typical for the very reasons Patrick mentions.

On the exam, if the question is written reasonably, it should not matter which of the two you assume, you should still be within acceptable range of the desired answer.

 

[PE_4_Panda]

I'll put it this way - if I did my work as shoddy as these engineer's write texts I'd be unemployed fast. Time to push back and ask for a refund. If enough of us do that maybe the publishers will get the hint. thanks, Jason

I wonder with all the errors is it worth the headache buying this book by Huang for $60? Also are the Ruwan books the only good resource for Construction PM practice probs?

 

[ptatohed]

Has anybody tried this problem # 33? I think while calculating concrete deck load, writer did wrong.

the load due to decking in one of the abutment would be 1/2(150*40*15*8/12)=30000 lb or by linear foot method 150*15*8/12*=1500 lb/LF along 40' length=1500*40=60000 lb since question ask for one abutment; divide by 2 =30000 lb (without considering truss load) writer has answer maximum 28000 lb.

Please help me if anybody has gone through this.

Thanks

Narayan

I totally understand the frustration when a book that you are trying to learn from has errors and, like you guys, I do feel that many/most/all of the errors should have been avoided and are inexcusable - but, with that said, it happens. Period. It's just something we need to accept. What I didn't "hear" one person here say is that they checked the PPI site for errata. The first thing I did before I even opened a book to study was write (in red ink) the errata corrections in all my references.

From, PPI's site, the errata for this #33 (and many others) is as follows:

Solution 33: The correct concrete load should be solved by: (150 lbf/ft2)(15 ft)(8 in 1 ft/12 in)(100 ft), which equals 60,000 lbf. The correct answer becomes 41,835 lbf per abutment after adding steel dead load.

 

[ptatohed]

If anyone needs help getting errata from PPI, just let me know. I know their site can be finicky. For instance, I can check their errata from my work computer but not my home computer. Weird. Anyway, just give me the book title, edition #, printing #, and your e-mail address.

 

[Jayman_PE]

That's an important point about PPI's website issue - I cannot access their errata post, read or otherwise. No problem accessing their purchase links though. Funny.

 

[ptatohed]

That's an important point about PPI's website issue - I cannot access their errata post, read or otherwise. No problem accessing their purchase links though. Funny.

LOL. Good point Jay. One of the admins at PPI explained in a post how to view the PPI errata. A setting in the Internet Explorer compatibility. See Post #5.

http://forums.ppi2pa...-Two-Problem-72

 

[Rybo5019]

I have the six minute solutions for civil or exam, construction depth problems, second edition- can’t understand how they solved scheduling problem #8 on page 4-3. Is there an error here?? Thanks

 

[civilrobot PE etc etc]

I have the six minute solutions for civil or exam, construction depth problems, second edition- can’t understand how they solved scheduling problem #8 on page 4-3. Is there an error here?? Thanks

What a coincidence! I just finished this section and I got the right answer so I don’t think there’s an error. 

What is your overall duration? Let’s start there.

 

[J46]

In a real reinforced concrete member you would never place a bar on each end. There is a region of concrete cover necessary on each side to protect the steel from corrosion.

101 is correct. The cover is an additional that's not typically included in the length.