Rankine's Lateral Earth Pressure - Active and Passive - Concept Explained and Example Problem

[@AFMathandEngineering]

This video wasn't our smoothest, but we tried to get the point across to you while skipping a lot of the derivation, which involves Mohr's circle, some other long concepts that would make the video very long. Hopefully you get something out of it. Click here for more soils mechanics material: kzbin.info/aero/PLv11OuQcvb_B9VwRekHywJTDwllNJYZ1E

[@truckynforky]

Learned more in 12 minutes than my class of 3 hrs lol, thanks a lot! God Bless

[@Fares_alhesni]

I’m seeing some audiences are not happy with this video, but For myself, it helps me to have better understanding of the topic. Of course need to read more

[@AFMathandEngineering]

Thanks! We know it isn't our best video but we're glad some viewers can get some benefit from it.

[@fjhking]

After watching multiple videos on this channel, i'm finally able to build in Fortnite while being attacked. +rep good building tutorials, really helpful

[@AFMathandEngineering]

LOL miss you buddy, hows life?

[@alizeeshan4432]

So much helpful Sir, so grateful from here.

[@gummadivijayraju1418]

Super..... nicely explained....

[@haroonjutt7501]

Nice video for active passive consept

[@chemarcay]

Very informative & concept explained well. Thank you.

[@davidgarza6988]

Great video on the math but stuill fuzzy on the concept - are active and passive earth pressure acting at the same time all the time? Active is the pressure that causes the wall to move but if passive is far higher how could the wall ever move? When you say "Passive is when the wall is allowed to lean in" what do you mean by that?

[@AFMathandEngineering]

Thanks, are you familiar with a basement wall in section? It's braced at all parking level s and ground so it's unable to displace, so we use at rest pressure. It's retaining soil from the outside of the building. If we look between the slab on grade and the footing, there will be a portion of the wall with soil on both sides. One will be passive, one will be active. It's hard for me to explain over a KZbin comment this concept, if you look at a basement wall section and look at the base near the footing you'll see what I'm talking about.

[@falcxn_dreadbot7732]

does neglecting cohesive pressure on the back of the wall means c=0?

[@dextergaming5974]

Legend. Thanks for the massive help!!!!

[@ijazullahsahebzada3203]

it was great thanks

[@albensmaine3057]

i litterally watch your vids during my 10 min study breaks x) and it's doesn't look simple , can we get an exercice vehicule related someday like the downforce applied on a F1 front wing ?

[@AFMathandEngineering]

+Al Bensmaine hey man, really glad to hear you're enjoying the content. Dynamics and mechanical engineering stuff isn't my specialty but I can always take a look and get back to you

[@Chipo122]

Do you have a video of Rankines earth pressure calculation under several conditions?

[@AFMathandEngineering]

This is our only video on lateral earth pressure currently although well be making more videos on basement wall design which will encorporate this concept. Stay tuned!

[@nickzimm5416]

Can you explain earth pressure coefficients when backfills at grade are involved?

[@AFMathandEngineering]

If you're referring to an open cut basement wall that's poured and backfilled, that would be either active or at rest pressure on the wall, depending if it's braced by slabs or if it's cantilevered. If you're talking about piling dirt beside a foundation wall that acts as a surcharge, this adds an additional load on the basement wall 'q' that must be accounted for. Usually we assume either 4.8 kPa or 12/14 kPa depending if this area is available for construction vehicles or trucks to access or just pedestrians.

[@nickzimm5416]

AF Math & Engineering say Beta is angle of backfill, as in my textbook. If Beta equal zero (ie. no grade) we calculate the coefficients of active and passive pressures the way in this video. If Beta /= 0 (ie. graded), there's a much more complicated formula for the coefficients. This is all Rankine method. I can do K_a decently. I'm having trouble knowing when and how to do K_p. Do you know of what I mean? Also, thanks for quick response.

[@suriyaprakash943]

Cohesive soil is this?

[@gabrielbobmarley]

can you guys do a block retaining wall design please?

[@bloggergirl3916]

Hi, I'm trying to do an assignment for my uni on retaining wall design. I was wondering how would I use the active force found since its in kN/m. If i were to get it to just kN, which length would i multiply by to get the pressure force acting at the particular point? Thank you!

[@AFMathandEngineering]

Hey thanks for the comment! Typically we design per meter length of wall and would just multiply by 1m to get it into kN. Without seeing the question that's the best I can do for you! Hope it helps.

[@bloggergirl3916]

Thank you so much for the quick reply! So technically you would just multiply by the depth of the wall into the page?

[@AFMathandEngineering]

No problem! Happened to be on as you posted. Yeah you multiply by a one meter depth into the page and design for a one meter strip of wall.

[@gabrielbobmarley]

@@AFMathandEngineering Do we use the active or passive to design a retaining wall?

[@AFMathandEngineering]

Depends on the retaining wall type.

[@flowerpowerocks3283]

i dont understand the stress diagram for the active earth pressure. Why is there a positive side?

[@AFMathandEngineering]

If you don't have clay, there is no negative. Hence the c value. Your geotechnical engineering textbook will have a good explanation of this.

[@musicbox14332]

Thank u soo much sir .. Where are you from ??

[@AFMathandEngineering]

Canada! Yourself?

[@juniorlwazi6137]

Good example but you make a lot of short cuts, so its kind to be a difficulty to follow all your procedure if you want to start to learn this theory

[@AFMathandEngineering]

The purpose of most of our tutorial videos isn't to learn all of the theory behind the problem. If you feel like you're missing theory you need to go to your textbooks and do some reading. We purposely leave out quite a bit of theory so we can 1. Keep the video to a reasonable length, and 2. We're focused on teaching you how to solve the problem itself. I'd suggest finding other youtube channels if we haven't included the theory or just do some reading on your own.

[@elizaphanirungu9104]

A nice video though some formulas just appeared so randomly ...derivation???😂😂😂

[@AFMathandEngineering]

Thanks for the comment, occasionally we go through derivations when we feel they're important/don't take too long, our main focus is to show you how to solve the problems and point out any potential tricks that you may come across. Also if you're in structural engineering you almost never need to understand geotechnical formula derivations as values are almost always given to you by a geotechnical engineer.

[@mobyshun7885]

paganda ganda naman po ng sulat

[@musicbox14332]

It's good ..but not going to brain

[@AFMathandEngineering]

Thanks man..this video we weren't the happiest about but we thought there was still quite a bit to get out of it. If you have a geotechnical textbook for your course its best to read the theory behind lateral earth pressure to see how the formulas are derived! We know this topic can be difficult.

[@musicbox14332]

Today GTE exam ..

[@AFMathandEngineering]

Ah...good luck!

[@babakiani]

Not very helpful. This video does not cover the concept and neither the common exam problems in this topic. At the end simplest possible problem was solved for Active and Passive Soil Pressure by just plugin the variables into the equation. :(

[@AFMathandEngineering]

Fair enough, thanks for the feedback!

[@babakiani]

I really appreciate your effort. I watched some other videos from you and feel they were really great so I think you raised the bar. Again thanks for sharing science and it's the biggest charity.

[@AFMathandEngineering]

@@babakiani No problem, if you read the pinned comment we weren't really happy with this video but posted it anyway as there's probably at least something that someone can learn from it, but it's definitely one of the worst videos we've made. Glad you enjoyed some of our others :)