Probably a very basic question, but I've been out of school for 30yrs.
Why does vertical stress from surcharge loads spread laterally with depth (e.g. 2:1 estimates) while they are treated as uniform with depth for lateral earth pressure?
Section 6.8.5.2 Clarifiers, page 446, the Camp scour velocity equation - handbook defines the particle diameter units as inches. Surely this unit should be feet, otherwise the units for velocity don't work.
Trying to work prep problems that apply the USGS culvert discharge equations. I'm not a drainage guy.
I can't get my head around this problem and solution. The culvert diameter is 4ft, the culvert height D is 3ft, the HW depth is 5.5 ft. This is a circular culvert.
The only way I can see this being possible is if you partially bury the culvert. However, if the culvert is partially buried, the active area (that carries flow) will be less than the full area (i.e. less than ...the 4ft dia area). The solution to this problem uses the 3ft spec for D in the equation, then calculates Ao using 4ft.
Is the solution wrong? Or is there an assumption that the inlet is buried a foot deep but the main length of the culvert is fully open and able to carry flow in the full 4ft dia? I'm reasonably sure this book is at least partially AI slop generated, so unsure whether this is my ignorance of drainage practices or nonsensical specs in the problem itself. What say you?
Trying to work some practice problems, asking for passive earth pressure at the base of a wall, in a cohesive soil. Looking in NCEES civil handbook v2.2, p74 gives these equations for K:
The solution in my prep material uses the std (no cohesion) equation for Kp, tan^2 (45+ phi/2). A reddit post from years ago claims these K equations were an error in Handbook v1.1 and were corrected in 1.2 and 2.0 - yet here we are in v2.2 with the same equations. Going down the YouTube, Google, and AI rabbit holes has not provided any clarity...the equations for p'a and p'p are correct and found elsewhere...these Ka and Kp formulas don't seem to be anywhere else. I'm not a geotech guy, and not particularly bright...any ideas what is going on here?
I'm preparing for the WRE exam, and have worked through the Petro book and the Solved in 6 YouTube playlist. While looking for additional problem sets, I came across this title:
Branson T. Dawson
"Master the PE Civil Water Resources & Environmental Exam: Full Breadth + Depth Review with 160 Exam-Style Multiple-Choice Questions in CBT-Style and Step-by-Step Solutions".
Not a lot of reviews, some reviewers call out inaccuracies in the book, with one showing photos of obviously wrong simple math. Look at the author page and its a generic, obvious stock photo. No details, just claims that the author is a licensed engineer, with several CE PE test prep books. No online presence, no social media, name does not come back in any searches other than listings for these books.
I don't think the "Branson Dawson" even exists, I think it's a fake name, a front for AI slop. Anyone have opinions on these books and/or whether this "guy" actually exists?
Mazda CX-5, turbo 4cyl 2.5. When driving at very specific speeds, around 51-52mph cruising in top gear, there is a faint but noticeable high pitched whine noise that seems to come from the engine bay.
It is only noticeable at this speed, starts around 51-52mph and disappears by about 53mph. It is not super high pitched, more whine than shriek. It does not sound crunchy or have a rattle or the sound of metal on metal.
Is this just an inherent thing with a turbo spinning at low range, or is it a problem in the making?
Just started prep for the WRE, been out of school for a very, very long time (>20yrs).
I looked at the free sample excerpt of the exam today. Question 21 seemed straightforward enough, backwash lagoon dimension requirements.
But the question and solution don't jive...question describes the filters as "The facility has four 12-ft^2 gravity filters."..to me, that reads as the each filter has a total area of 12ft^2. The solution assumes each filter is 12' x 12', 144 ft^2 area.
Respectfully, WTF? Why not phrase the question as the filters having a dimension of 12' x 12'? Do others perceive this solution as a flawed/ error riddled, or am I dumb and missing something? I mean, I get that in the real world the filters are always going to be larger than 12sqft, particularly with the flows described, but words have meanings and I interpret the question precisely how it was written.
Are there other errors in these materials? Investing in the prep materials and time to take this test seems dubious if this is the QC I can expect from NCEES.
