How To Build an Engineered Retaining wall & Avoid Contractors that cut corners

[Music] this is the perfect cross-section of a retaining wall you can see where all the drainage aggregate is and then you can see where they structural fill soil sighs all right guys we're gonna be building an engineered retaining wall today but we're going to be talking about the difference between an engineered retaining wall that holds up a load which is this one and then on this exact same site we're gonna be building the identical retaining wall identical height over here that does not hold up a load and so we're gonna actually walk you step-by-step through the process on how to build an engineered retaining wall so the first thing I want to talk about real quick before we get too deep into this is when do you need an engineered retaining wall or when do you need to engineer a retaining wall and that is any wall that's over four feet in height or any wall that has a load on it and the load can be considered two things a hill another retaining wall or actually a structure like a house with so those are three things but technically any Lenny wall that's going to be under those circumstances you need to engineer even if the walls under four feet in height that three feet in height another thing that some guys are going to be looking at this video and going screaming is well my County my city my blah blah blah doesn't require it who gives a crap you're building a wall that you need to last for the customer a hill another wall those things don't care if the county requires you to engineer it or not because they will eventually push your wall over and make it fall down if you don't build it the right way that's the difference that we're talking about so whether your county requires it or not isn't the point the point is you need to engineer now let me show you something let's go let's actually look at an engineered plan [Music] all right now would also be a good time for me to jump in here and explain the difference between a reinforced retaining wall and an engineered retaining wall which I don't necessarily the same thing a reinforced retaining wall means that it has geogrid in the retaining wall but that doesn't mean that the retaining wall was designed by an engineer you see there's very few people that actually know how to design retaining walls a lot of guys will go out and actually have a civil engineer design a retaining wall for them and I'm gonna tell you straight up that's a big no-no no I know I'm going to have a bunch of civil engineers jump on here and tell me I don't know what I'm talking about but I've tried to build retaining walls after a civil engineer has designed them and they usually have way too many things wrong with them they're either built overkill or underkill and they're not designed specifically for the application that they are needed now there are retaining wall engineers and those are the guys that you want to design your retaining wall and a retaining wall engineer is a civil engineer that has specialized in retaining wall design they can they account for the types of soils that you have the type of log you have but then they also get into the mind of the installer and understand what it takes to actually accomplish this job that's the third most critical element into building an engineered retaining wall now remember a reinforced retaining wall doesn't mean it was actually designed by an engineer an engineered retaining wall will typically be a reinforced retaining wall that is actually put together and designed and drafted by a licensed certified engineer that has experience in retaining loss sorry for taking so long to explain that but I think it's pretty important that you guys know the difference [Music] Southwest wall 250 PSF so this wall right here is designed this one behind us to hold up a parking pad right here and you can see that this is an 8 foot tall wall so these horizontal indicators are actually the geogrid length now this wall is 9 foot or this these grids are 9 foot 6 inches in length we're gonna flip the page and we're going to show you an engineered retaining wall same height different circumstances the grid lengths shorten up by 2 feet this is only a seven foot six inch geogrid length here but the layers of geogrid don't one two three four five six layers of grid in this wall and on the wall with the load one two three four five six layers of grid so you can see that there's a few different elements that go into engineering or retaining wall and we're going to show you step-by-step what they are what we actually build a wall now I think this would be a good time to jump in here and tell you one of the things you don't want to do with a retaining wall and that's plant a tree on top of it now bushes and shrubs are okay but a tree actually represents a dynamic load as that tree grows upward the roots grow downward and push out the retaining wall is not designed to resist that kind of movement and then on top of it when the tree experiences high wind and the tree starts to move in shape from the wind that adds dynamic force into the wall below it that can lead to premature failure so bushes and shrubs Brocade but trees I'm holding the camera and as he's filling the bucket I can't help but you see the camera jerk like this every now and then it's been just my instinct to I'm doing is and technically I'm catching myself bucket flipping the material up and into the bucket even though I'm technically not in the machine and I'm literally holding the camera I still can't help it I feel like I need the bucket flip sometimes alright guys so when we build an engineered retaining wall it's not excavating back for the depth of the block and the depth of the drainage angry at which we can see over there can you pan over there real quick you can see all of that material we imported how many tons of the imports like 64 time just for this portion of the retaining wall alright guys so when you're trying to figure out how many tons of rock you need for your retaining wall project measure out how many square feet of wall you have multiply that by 200 and that will tell you how many pounds of rock you need because the formula is 200 pounds per square foot of retaining wall then you take that number and divide by 2,000 to convert the pounds that you need for your wall into tons because that's how it will be delivered out to your job site so let's recap this take the square footage of your retaining wall multiply it by 200 that gives you how many pounds of rock you need divided by 2,000 and that converts the pounds into tonnes pretty straightforward right here the excavation area is Paul all the way back here because we got a late children in here we got it actually for this 8 with Tom wall you have six layers here that's because we got a surcharge so we're designing this wall to be able to hold up a car eventually up on the top it's a completely different design than a standard gravity wall and a completely different design than just a normal engineered retaining wall that has no surcharge or no [Applause] so you've gotta realize do you think you need to think ahead when you're building a retaining wall what's going to happen during the light this wall will it something up [Applause] so you can see we do not let the geogrid come all the way through the face of the retaining wall because that looks like a hack job that's as simple as that but we get it as close to the front as possible so when Blaine's cut and grid he actually picks a line and he stays in between the line I'll get try to get as close as I can to show you guys not rocket science but I see guys cutting the backside of their grid higgledy-piggledy and what happens is your next grid next time you use that grid you're not gonna have a straight line to go through the face or it's not gonna have a straight edge to go up tight to the face of the wall without it coming [Applause] all right while we're talking about grid we also need to explain the orientation of the grid because there's a right way and a wrong way to this as well you see if you have a 200 foot long retaining wall you can't just roll the grid out behind the whole wall parallel to it and say that it's good that's not the right orientation the Geo grid needs to run perpendicular to the face of the wall so if your wall is right here your grid has to run this way behind it and can't run the long way behind it it's just not meant to do it don't do it Johnny neat says don't do it don't do that I so let's take a cross look and what we've got going on here we're in the middle of a demo of an existing retaining wall and this wall isn't that old I can tell by the block they're using but do you notice there's no drainage aggregate in it and when you look closely at the soil behind this retaining wall you can see that there's zero-g over it in it and you'll also notice that this wall was initially installed as a double terraced retaining wall which is a typical tactic that a lot of landscape companies will use when they're trying to circumvent the need for engineering well what happens is when you put a double terraced retaining wall in is you literally need to take the light of the bottom wall double that and that's where you can then start the height of the second law so that the second wall doesn't place a surcharge or a load on to the bottom wall you'll see in this job site that none of that was done and across the United States of America unfortunately it happens way too often and there's no material locking it together we do have some mixed in but the rock that you see mixed in let's go in tight seems like you that would be good base but that's river rock it has a little bit of angular stone in it but it's technically a half inch river rock not doesn't make a good bass and how do you know well take a look at the corner do you see where we go sagging down we do not want river rock up as backfill or as drainage zone because it doesn't lock in place the block they used is the whole reason why this wall even is lasting as long as yes that's an excellent block because there's so much mass to it just such a monstrous block that it accomplishes the job even when you don't do everything behind the wall the right way take a look at good drainage aggregate right here this is angular stone locks together when there's rain in the forecast and we know we're not going to be on-site we do mall our piles compact any open excavation areas and spots that we can't compact we tarp that way when the weather cooperates we're ready to get right back into work [Music] looks good guys you'll be done by tomorrow right when you get into a big project like this sometimes your plans change on the fly now in an ideal world the corner that butts up to the house would have been a radius but here's what happened it was too tight of a radius to make it work without compromising the integrity of the blocks at least by going with a 90-degree corner in this situation we're able to overlap each block this is that we can build upon it in the inside 90 degree isn't quite as good as an inside radius but if you don't you don't have the room to make an inside radius than an inside 90 degrees you next best bet because it's your only next best path right so let's go look at the backside and the magic that makes a 90 degree inside corner work now I haven't seen this so we're gonna be testing Blaine and seeing how well he does so playing can you actually hold camera for me because this is a really well-done 90 degree inside corner this is actually an over built 90 degree inside corner one of the things that I want to point out to you guys is that ninth the 90-degree corner is actually here and Blaine's actually got it over built all the way over here because now instead of cutting half C's or half blocks he's utilizing a full block it does eat up a little bit more material but the longevity the strength of this 90-degree corner in comparison to something where you literally snip blocks in half there's no comparison this is the way you want your 90-degree corner so let me let me come in here and show these guys exactly a close-up of it you can see that the 90 degree actually stops there and he's built it out that way he's built all the block all the way up on top of each other and brought it all the way back we see see Franklin look at this this entire block right here isn't even needed technically but in our book that adds strength to the entire inside corner so add it if you can add it it's the right way to do it this was my house this is how I'd want my 90-degree corners bill and least you do one thing right Blaine actually I will go on record as saying Blaine and Todd are craftsmen nice 90-degree corner nice nice nice alright another thing I want to look at it of these lifts so take a look at this lift nice literally when was the last time you guys see me out in this job week and a half two weeks ago right and I didn't I don't ever tell you when I'm gonna stop in so it's not like you did this the reason I asked it's not like you did this for the camera this is the way we operate so you've got a lift it's compacted the grid is folded up it'll be folded out when it's ready to go the dirt isn't left unfinished even where we step down now this gets to be a little bit of a tougher area to do but even on the transitions down this is what I call rain ready Todd will you grab this camera really what I want them these guys to see is this transition can't be left loose right here so you've got your elevation established here and if you just let this soil go without compacting it and you leave it rough it's not going to be compacted when you go ahead and put your transitions or your lifts down below you're gonna always have these little tiny areas which can have settlement with these guys have done is they've compacted all the way down even in the areas where it's more difficult to compact especially when you're using a thousand pound plate packer like this can you see that in here Todd this is a beefy piece of equipment it's not easy to run it up and down but this is where they've got it parked right now because they've been packing the transition zones as well as the lifts and we just walked up and we've seen them putting a lift in we've got let's actually look at the lift right here so we can see you can see right here it's all compacted solid and then I think you guys just literally put a four or five inch lift in yeah I mean and realistically you could put a six to eight inch lift in but with this way we know we're not gonna have any settlement down the road this is the perfect cross-section of a retaining wall you can see where all the drainage aggregate is and then you can see where the structural fill soil starts and then this gets compacted the grid gets laid out and about a bing bada boom onward and upward [Music] [Music] okay guys now this one is good to go the top of the wall here's a little fun fact for you you can never compact within three feet of the backside of a retaining wall that's just the DIA the technical G engineering term that's what they tell you we get a little closer than that alright guys we went a little deep today I hope I didn't lose you guys you guys got to tell me down below did I include enough detail and enough information and if so is this the kind of videos that you guys like because if they are then I'll try to make more of these guys to help you out so when you're going out and tackling your own project you ought to know the difference between a reinforced retaining wall and engineered retaining wall or if you're looking at hiring a contractor making sure that they're doing the proper building techniques so that when your job is done you don't have to call anybody for all very long time because it's done the right way I hope this video has helped you guys out you get

Channel: Stanley "Dirt Monkey" Genadek

Views: 442,215

Keywords: retaining wall, diy retaining wall, engineered retaining wall, engineered retaining wall plans, how to build an engineered retaining wall, how to build a retaining wall, build retaining wall, retaining wall design, retaining wall ideas, retaining wall installation, retaining wall drain, how to dig for a retaining wall, retaining wall mistakes, retaining wall construction, retaining wall diy, geogrid retaining wall, geogrid installation, how to build a tall retaining wall

Id: J48kyZfq50M

Length: 19min 46sec (1186 seconds)

Published: Fri Oct 19 2018