Before You Dig: Earthworks, Geotech & Stripping Plans

You want me to strip what? Today we're talking about earthworks and how you can lose your shirt before the building even gets out of the ground. A few test holes, a good geotechnical port, and a proper stripping plan can save you hundreds of thousands of dollars right from the get-go. Let's get into it. Welcome to What the RFI. I'm Matt Brennan and this is the podcast all about CA. If you haven't already guessed it, we're going underground. What I mean by that, we're going to talk about earthworks, the geotechnical reports, and stripping plans, the valley behind them. This is one of the biggest areas of financial risk right at the beginning of a construction project. You've issued for tender, you've got to award the contract, and you're ready to get going, you're exciting. The excavator's out there, they're moving dirt, and something happens. We're going to get into those details today. In saying that, that's where you can start with a great set of drawings, a great contractor, no issues there, even a healthy budget. Then you just start digging and that's when you discover the ground is not anything like you expected, period. Suddenly, that $100,000 earthwork budget, well, it can become a million dollars in extras right from the get-go. CD1, there you go. Today, I want to walk you through in detail how to manage this risk, how to prevent it, how to be mitigated, how to be proactive. We're going to dive in all those details in today's episode. We're going to walk through items such as who should hire the geotech engineer, how many test holes are good enough, what is exactly a stripping plan. I've said it a few times, what is it? What does it entail? How should the earthworks be tendered? Maybe you want to do a separate earthworks tender, but the point is whether it gets a separate tender or if it goes part of your billing package, it's something that we need to go into the details of it. What happens when you do start digging and everything still goes sideways? What do you do? That's what today's episode is all about. First part of business here, who hires the geotech? In my opinion, and what I've seen over the years, and it makes total sense, is the owner, and repeat, the owner should always retain the geotech engineer. Why? We'll get into that in a second, but the architect on record will always hire the consultants being structural, mechanical, electrical, building an envelope, civil, depending on the project. Sometimes the owners like to hire them out. I don't see necessarily the need of that, but the geotechnical and the surveyor is always, those are the two consolents are always retained by the owner. Why? It comes down to risk and liability. I want to keep them at arm's length just in case something hits the fan. That's what this episode is about. We basically design anything above the ground, really what it comes down to. We can't guarantee what mother nature put underneath it. Maybe this was a test pit, a fill site for another, for a different job where they dumped everything. We just don't know. There's too many unknowns. You can't really, unfortunately can't x-ray it or run drone technology or anything crazy. You just don't know what you're going to get until you start actually physically digging in that sense. If the geotechnical information is wrong, the financial exposure can become enormous, and that's why. That's why we let the owners hire the geotechnical. We do recommend as the architect on record, we will suggest who we, we know the guys in the business who are firms in the business that do well, that get it. I've worked with some geotechnics that I've never worked with before and it's been fine. We have also worked with some geotechnics where we encourage the owner to let them go because they were making some pretty big, right out of the get go. They were making some pretty drastic financial red flags that were there. They were just making some errors that we didn't agree with. We brought a second opinion on and we saved the owners close to a million dollars just because of one person's opinion. So by the end of the day, we didn't retain that geotech. We always let the owner do it. So owners hire the geotech and away you go. This leads into the initial geotechnical investigation here. So early in design, the geotechnical comes to site and performs a little investigation. This is even before design. Let me just take a step back. Maybe there's a project definition report or they just want to get some ideas on this new site that they acquired or they're looking at a site. They may get a geotech before the architect comes on. They'll have a general report what to expect, high level stuff, right? But they've physically done some test pits. In that report, there might be like two, three test pits, boreholes to pay on the site and the project. Then through that, they're looking at the organic materials, soft and suitable soils, clay, bedrock, groundwater, existing fill, compaction conditions, where they're actually hitting bedrock if they even do, if you're building on top of a mountain or something like that. But through that, basically they'll perform a 2050 page geotechnical report, which will lay out what they found in that really preliminary investigation. Again, they may draw it. Did two drill holes, two test pits and went from there. Like I said, hopefully that report, they would look up some previous data. What was the site used before? Like I said, was it a fill site, historical geotechnical information? And just again, any and the other soil conditions in the area. But here's the big problem with this is a couple of test holes are just a tiny samples of a very large site. It's not going to tell you very much. You don't exactly what is between those holes. So that's kind of their first crack at this site that the owner is possibly looking at. They hire them, they do the test holes, and the report sits, and they've got a record, and they can make an analysis based on what they're finding on that initial data. Is this worth even going ahead? Maybe they don't have a choice because this is the only site they have to work. If they're a school district, they have to work with this site anyways. So it just may be the reality is. Now, basically, the architect comes in, start designing. We have the geotech report, have some ideas, but again, we kind of, you know, it's really high level. At this point, once you've got that building footprint relatively ready to go, you're in that schematic stage. Now you're like, okay, now we're starting to go ahead into CDs, construction documentation. Where you're kind of starting to pursue a building permit before you even get to that point. But once you know when you're confident that your design development and your schematics kind of wrapping up and you're going into that CD stage, this is a fantastic time to get that geotech on the phone, give them a site plan, and say, I want some new test holes. I want you to go back out there, okay? He knows where the building is. He has a floor plan. You can even start saying, look, I want a couple test holes that gridline 3B and maybe one, you know, do a handful of them, right? It just makes sense. And some of the key areas I definitely would look into is around the elevator pits, the around the gymnasium footings. They may be a little bit bigger. If there's any, you know, in preliminary design with a structural engineer, is there any brace frame areas, again, where they're going to tie into the foundations? Any heavy structural load areas, very deep, deep foundations, I'd like to know this as well. And just any kind of other general critical areas about it. So in this case, I would target at least an additional two to six holes, maybe more, right? It all depends, okay? It's cheap for them to get the rig out there. Or it's not cheap. It's there's a cost to mobilizing it. But for them to do some additional holes, it really doesn't matter. It's just their time of day. And if they have to spend an extra day or two out there, it's going to be, you know, considered as cheap insurance. Okay. And this, like I said, just ties into spending a few thousand dollars investigating the ground before the tender can be potentially save hundreds of thousands of dollars. And I much rather discover bad soils now before we tender than discover it after tenders close, contractors are on site, and they start discovering some unfortunate news. You know, that wasn't part of this geotechnical report. We have nothing to stand on. Okay. And this kind of goes into the stripping plan. What is a stripping plan? All right. And what a stripping plan is, is we take these investigation holes that we did on site, we take that report, take all the additional holes, take it with our civil engineer, and then they overlay it. And they basically think of it like as a heat map. All right. So, you know, some of the test holes in kind of like we'll say on the left side of the building were, you know, we were realizing that we need to strip down two meters. Okay. But as we kind of went from left to right of the building, the test holes started telling us to go down to four meters and then the holes on the far right side of the building. Well, they want us to go down six meters. This is where you could basically do kind of, you know, a color coded legend where it shows where the two meters are, the three meters are, and then the six meters. And what we're doing is we're kind of giving, we're creating a tender package that's kind of, you know, for a tender application is kind of apples to apples. Bidders are going to be bidding on the same thing. There's no assumptions. Well, this test hole isn't I interpreting it while we only need to take out this. We're creating a simple level playing field with this. Okay. And I just want to take a step back when we're talking about the geotech. When he was out there doing his additional test holes for us based on the site plan that we've provided them. If there was anything that came up that was some immediate red flags, and as they started getting into the holes and digging at that point, do some more. As I kind of noted, you already have them mobilized on site. The drill is already out there. It is very inexpensive and cheap insurance just to keep going. So more holes, the better. And that's going to start to define a really well-defined stripping plan. This heat map that the civil engineer is going to do. Your geotech is not going to do it. For some reason, I've pushed them to do it, but they've never done it. We just go to our civil engineer and say, can you kind of plot out this contour where this needs to be stripped down? Okay. And like I said, in this kind of the stripping plan, there may be some pockets of some definitely much deeper areas where we need to go down to that suitable grade. But at the end of the day, this is like I said, the stripping plan is going to help. And the other thing, instead of the bidders trying to interpret a 40-page geotechnical report for themselves, they may not even look at it. This gives them a simple, clear drawing. And I think that in just being fair and the interpretation of it, it's something that really helps. Plus, it helps us understand it, helps the structural engineer as we go right into our CDs and wrapping it up for the building permit and then eventually preparing them for a tender package. And what that tender package is going to include, it's going to include the stripping plan that we talked about. It's going to include the full geotechnical report. Now, I want to pause at that point. It's going, the geotech would have taken his original report. And if some other geotech did it, but we brought a different geotechnical on board, they would still probably reference the old one. So you're going to take the old report, maybe the update the report, it all depends. But at the end of the day, this is going to be the finalized report with the new test holes, with the stripping plan. And we'll have clear earthwork quantities and requirements based on this data. And one thing in our bid forms is we're going to put in there that we want the contractor to provide us with some unit rates for materials in and material out. Okay. And what are unit rates? Why are these critical, Matt? Well, I want the units rate, I want the unit rates established a tender. So when on the bid forms, when the contractor submitting their formal tender bid, they're going to write out saying, if I have to strip more material that's outside a contract, it's going to be 50 meter, 50, $50 per cubic meter, cubic yard, whatever, you know, a cubic foot. Whatever the case is, they'll note their unit rates in and out based on what they found, based on the geotechnical report. And as for any unsuitable material that needs to be removed. Okay. And this has been approved for the structural fill brought in as well. Okay. And now every bidder is pricing the same thing with this, right? We have a clear vision of what's going forward. We can review the unit rates in that sense, and that's okay. And like I said, this tender package is now apples to apples for anyone bidding the job, which is fantastic. It's going to help up tighten up the bids for us when we basically bring this together. And then down the road of once we get into construction, we know we have an idea what to expect if things do go sideways. Okay. And the more importantly, if quantities change during construction, like I said, we've already have an agreed method for calculating the cost, right? It's escalation or whatever changes. We've got it. Okay. We're not trying to negotiate the earthworks pricing while the excavators are running. Trucks are waiting. The schedule is starting to slip because of this and everyone is under pressure. So again, it just sets the playing field. It sets the groundwork, the process going forward, and we know what to expect. Now the fun begins. The construction starts. We've awarded the contractor. We've got three unit rates. They bid competitively on the tender package. The contractor gets the IFC drawings. They mobilize. They have the stripping plan, the geotechnical report. Tender quantities, the unit rates, excavators start to show up on site. They start digging. Everything is going great until it's not, until it isn't. And the geotechnical said the suitable bearing was at two meters. Well, the excavator hits the two meters, still garbage. Three meters, still garbage. Four meters, we've got a problem. A big problem. And this is where an emergency site meeting would take place. Contractors are going to pick up the phone. He's going to call the architect. You need to come out to site, bring your geotech, bring your structural engineer, bring the owner, and you may want to consider the civil engineer, right? At least get them on the phone. But ideally we need the team to come out here because we're hitting problems with this. And we really need to make a fast track decision here because, well, the excavation can't just sit there. Excavators can't, you know, the contractor's on there. They've signed up for a tight schedule. They've committed to a schedule. And this is something that's going to change the game for them. Okay. With the geotech on site, we're at this emergency site meeting. The geotech needs to determine if, A, do we keep digging, right? Let's review the soils that we're currently at. Maybe do we change the fill strategy? Probably not. Chances are we're going to just have to keep digging. Okay. Can we look at modify compaction? No, that stuff, what we're digging up is complete garbage. We need to keep going. Okay. Is there a structural solution? Where is the suitable bearing placement of this soil? It's hard to say. Okay. This is why the more investigation we can do at the beginning is going to save your ass entirely at this moment. Okay. And if any additional work is required beyond the contract here, this may become a change directive. We've talked about change directives on the show. I'll put a link in the description below. I'll put a link above and all that stuff. That's great on its own. This is where a CD makes 100%. It makes total sense. You can't do this as a proposed change or a contemplated change notice if you're out here in Canada, BC in that sense. A change directive basically is an open checkbook. It says, go ahead contract. You've got our full permission. Start digging. Start doing what you need to do. And there is some ground rules and we're going to get into that. But what it's doing is that it's basically just telling the contractor go. We'll figure out the total cost later. Okay. And as we write up this change directive, and again, I highly recommend you listen to that other episode. But if you're, if you're issuing a change directive, what you probably are, there's nothing you can really get out of this. CD one. Here we go. This is where we want to make sure we're tracking everything. Well, we're trying to do it right. And this is where a good construction administration becomes extremely important. What I mean by that, if we're proceeding before the final cost is known, which is the purpose of a change directive is we want to document the direction very carefully. Okay. We want to photograph the existing, existing conditions. We may even survey it, drone survey it as well. That would definitely, definitely the survey. Having drone technology is very cool. And there again, I've got an episode coming up on that. We want to make sure we're recording the depths. We want to record the quantities, how many trucks are going in and out track every truck if possible, you know, keep an eye on it, leaving site. I've been in those arguments before what we've looked at. I went, there's no way there was 30 trucks or 50 trucks. Our geotechnic on site actually counted 30. He was paying attention again, cheap insurance for what this gun can cost. Okay. Have that geotechnic out there regularly. As they go from test, you know, from hole to hole to test hole to test hole. They may keep finding bad soil. It might just be a, a, a, a, like trying to catch a falling knife here. It may just get go from bad to worse. So really track that, have them out there, you know, every second, third day, you know, it's a constant communication with the contractor and, and, and put that in your change directive. Okay. But definitely every few days is necessary and don't wait for the holes to be filled back to start arguing about what was removed. Like is that track at all truck counts matter, right? They do. If we're paying by cubic meter, we need the evidence, right? And this is why the survey plan of the, you have your existing survey, have your new survey. That's going to be really clear. And that will go against what was known as the stripping plan. So basically anything from the stripping plan and downwards is going to be a legit extra, very simple. Okay. And contract is going to track the quantities. Consolants are going to verify it, right? The geotechnic in this case, he's the one that's going to be looking after it. And the owner is going to have that documentation. They're going to want to see that. And when the final change order arrives, we're reviewing the records, not the memories from this lovely incident. These scenarios suck, right? I've got a school that's actually, that's exactly why this podcast was inspired. This episode was inspired that because that's what we had. And I've been in and through another few schools where we've seen that work, even if we've done our due diligence and we just couldn't get away. We just, by luck of the draw, we put those test pits and they were decent soils and then, you know, 20 feet to the right of them and 20 feet north of them. They were just bad soils and they've just got into bad pockets and then some good pockets. And it, it's so hard to say, but the more you can do the investigation at the beginning, it really, really helps. And do watch out for the unit rate argument. Some issues can come up is the soil that we're moving isn't the material based on the tender, what we looked at. And that's a fair statement. And they may want a different unit rate. And that's something just to look at from a contractual point of view. You have to look at how your tender documents were put together, what the geotech report, what the specified unit rates kind of called for the actual site conditions. And I think it's just one of those things. This is one of those things that's just, there's risk not only to you as the owner, but there's definitely risk to the contractor. And I think just being very sensitive in this matter and doing it right, being fair and reasonable from both sides. It's just one of those things. This is the first change that you're starting with this new relationship. You're going to be in bed with this contractor for the next two years. So do it well, do it out of respect. And at the end of the day, they need to eat. They want to get paid. They want to pay their teams to do this. And this is why you have a contingency. This is why you do your homework at the beginning. Why you do those additional test holes. Why you do the research of the site if you can have that contingency. And then, yeah, and just the reality that this can slip the contract or the contract timeline, the schedule as well. And that's just the way it is. Okay. But just, yeah, understand that there may be a genuine difference between this. And of course, have your proper documentation, do your homework before, you know, concluding it. And then wrapping up this finished paper trail. So once this earthwork is complete, hurrah, finally, hopefully there's no more surprises. Oh, guess what? We found a giant rock in there. We found a bunch of stumps. We found a bunch of boulders. What do you want to do it, owner? Do you want to throw them in your new playground area? Maybe that's up to you. Once this is all done, the contractor is going to submit all those quantities for that change directive. They're going to submit the supporting documents, the invoices, any of the tickets, confirm the truck counts. The geotech is going to verify all this information, the quantities where it's all applicable and go through it. The consultant reviews against the agreed unit rates, simple math. As I noted, we'll take the new survey of the final strip down depth, and then we'll compare it. We'll compare that to what the stripping plan showed. That's going to show in that scenario. There may be some additional costs because of the way we have to slope the banks. Keep in mind to that. All these things came into play. Your consultant team, your civil engineer, your geotech, will be able to look at this and totally understand how the costs are what they are. It should be, you know, basically, hopefully, a fair and reasonable based on that. But I have been on sites where they did try and double up some of the trucks based on the reports. We had backup documentation to prove it. And in the end, they didn't win their case. So, but again, hopefully you're working with a good contractor and it's not a big deal in that sense. So in the end, we get the cost in, we look at it, we approve the pricing and way we go, we finalize that CO. And this is why the documentation during the work is so important because again, you're just back checking your fact checking the data and the details. Okay. Because six weeks later, nobody wants to remember whether there were 72 or 170 trucks. We just want to get it done and get the project moving. We want to get those foundations formed up. We want to get that steel flying into site. It's tough when, you know, you get this kind of fortunate kind of black mark from the project, but hopefully, like I said, throughout it, you're in good shape and you've got a good relationship. There's no finger pointing. It's just what it is. You had bad luck on it and hopefully you can move on. Okay. So key takeaways, right? You can never completely eliminate this risk of what is underground. You just never know. You can't scan this. You can't do it. There's nothing like, there's no technology out there. If you know about it, drop in the comments. I'd love to hear about it. And you honestly, you can't test every square meter of a site. It's just not practical. It's not there. Otherwise you'd be stripping it yourself before the contractor even goes. It does. Like I said, I mentioned earlier at the beginning of the episode is you may want to break out your two tender packages. Maybe you want to do an earthworks package to speed up that process. Those are always a good idea. And then you can do it, but in a day, it's not going to eliminate the risk. You're still going to have that risk of this site. Okay. And in order to reduce that risk, dramatically reduce it is again, get a good geotech information, get a good geotech first of all to, right? The owner can acquire that. Um, do the additional targeting test holes around the building locations that you know of. There's no point testing where the field is, right? So it's irrelevant, right? That's a whole different thing, but where the billions going do those tests, whole special in those really critical areas, create that stripping plan. As we've talked about, establish those unit rates at the tender carry on the earthworks and then you can see the consistency when the site warrants it. Right. And when conditions change, document everything, everything. And because of spending, spending a little bit more money and understanding what's underground before tender. Is a whole lot cheaper than discovering it with an excavator, 20 trucks and a construction schedule waiting for an answer. Okay. Very important. Can't stress this enough guys. So what is the final takeaway from this? Well, there's an old saying in construction that you make or lose your money in the ground. Period. The same speaks for itself. And after watching a few projects, do deeper and deeper and deeper looking for good soil, I say it's a pretty accurate statement. Right. Do your due diligence. Do those additional test holes. You won't regret it. You can't eliminate every unknown underground, but you can do your homework, drill a few more test holes, get a good stripping plan together, establish that unit rate, give yourself a fighting chance for this. Because if you're going to lose your shirt on a construction project, or at least try to make it above the ground, yeah, architects keep designing contractors, keep making those blueprints reality. We'll see on the next one.