Principles of Measurement in Construction Projects

okay in this session we're starting with the interesting work and this is where the rules are coming in to be applicable directly to drawings so as we go along you must visualize things that you have been exposed to in arguments act the drawing subject or in the uh Building Technology module and so on and together with uh visualizing something you must also bear in mind any item where the action required impacts on the cost the moment that happens it is a separately measurable item so the slide that is on your screen at the moment you will see on the left hand side there I have a a shovel and on the right hand side there is a mechanical excavator so what is the importance of this and that is sometimes clients and specifically government clients want to restrict the use of um mechanical excavators because they want to create extra work so they will make a project subject to what we call Labor intensiveness so they can say that I want this project of mine to all be excavated by hand but it is not always possible to excavate everything by hand because the deeper the excavation goes uh it becomes impossible for a man standing in argument sake an excavation 3 MERS deep to Turf the soil out onto the surface so also there then uh there will have to be a distinction between how we go about these things but the type of projects where government makes this uh applicable are of course then uh simpler in nature where it is possible to excavate by hand okay so again I'm emphasizing anything that impacts on the price must be given separately so it's possible that you can be involved in a project where you have hand excavation and machine excavation and then you will have to uh set them separately so that the contractor can price them appropriately okay so let's look at the first Clause over there and this is a a general the heading over there is and the first Clause is Method and procedure so the moment there is a general Clause like this it means that this General Clause applies to all the other Clauses in this specific trade so let's see what is happening there on the method and procedure so the first bullet point that I have over there and if you have a standard system next to you or open you can jump there and you can see that these are actually the measurement rules that are in the second column over there so it says restrictions regarding blasting jackhammers mechanical excavators compactors Etc so the moment the contract is a restriction is put on a contractor where he cannot use any one of these pieces of plants or where he's only allowed to use his Jackhammer after hours arguments act because of noise any restriction like that must be listed in your stand in your bill of quantities otherwise the contractor will not be able to price properly okay then the second point over there the excavation or filling in a particular order as I said just now there are few exceptions to the rule but if this exception does apply it must be specifically stated um otherwise the pricing is going to be the general rule which would then be incorrect okay and the third point over there uh revolves around multiple handling and the specific Clause says prescribed multiple handling of material shall be included in the descriptions now let me explain to you the concept of multiple handling so on the on the next slide over here I have a a little diagram so what that is meant to illustrate is you have a site and you have column bases and between the column bases you have strip footings so if I can just get my pencil going over here so this is your site boundary these are your column bases and this is then your strip footing in between so when the contractor gets to sight he has an open sight he needs to put set out his columns and he needs to dig the columns so what happens is he's digging away so he's dug a hole so this material that comes out here needs to be placed on the surface somewhere and is going to dig as you can see nine holes on this site over here but what now happens if he starts on the first row over there and he puts this material that he is digging over here argument sake he puts it over there now when he wants to dig those two bases he needs to remove the Heap of soil and argument sake put it over there so that is very bad planning if there is space to put the material the contractor must put the material where it doesn't interfere with any other work so the the multiple handling that I'm talking about so when we're doing an excavation item the Excavating and placing of the excavated material on the surface is one item it is covered in one item so that material cannot be placed over here where a strip needs to be excavated or over here or over there argument sake or anywhere in the way the best place to place it would be over here or over here where it doesn't interfere with the rest of the excavations but now it is possible that you don't have a nice site like this where you have place to put that material let's say it is a confined space uh it's a site in the CBD of Petoria and you're digging in between two other buildings there simply isn't any space so the engineer or the architect will come and say to the contractor okay do your whole excavations and place the material where you can place it and then before you do the strip footings I will allow you to cart that material away and go and put it somewhere else because here is no place on your site and in that instance that is what we refer to as multiple handling because the norm is we excavate and place on the surface in one item the next item we will take from the surface and use that material for filling is the second item and if any material is left over we will take that material and cart it away from sight or we will spread it over sight or whatever we will do with that soil but the multiple handling comes in where placing is not possible um and it interferes with the rest of the work so that material needs to be handled once or twice so it's it's placed on the surface first of all and then it's removed somewhere else and in that case moving this the second soil is the multiple handling so the second action of taking the soil and moving it somewhere else to another site or somewhere outside of the site where it can be preserved for later use that is the second action and that is what we refer to as multiple handling so the first action is taking it out and placing it on the surface normally the second action would be taking it from the surface and using it for filling or something else which is a separately measurable item but if the second action is taking it and moving it somewhere else but not using it for filling that is the multiple handling okay and if that is the case due to the site conditions then the contractor is entitled to payment for it if multiple handling is caused due to his bad planning he pays for it okay but if it is required due to the a restricted site or something it must be specifically stated and the contractor will be paid for it okay the second Clause under General is bulking and the description says no allowance shall be made in measurements of disposal or cting away of material for bulking so I want you to look at this picture on this slide and you can see there is a very slim excavation over there but next to the excavation there's a huge heap of soil lying over there so that that already gives you an idea of what we are talking about that swell in its compacted form is smaller than swell in uncompacted form so our principle of net measure is soil is always measured in the compacted form so when I'm measuring that excavation that you see there on the slide I will literally be measuring the length of it the width of it as you see on the slide and the depth of it as you see on the slide and the moment it gets out over there um it is larger so the inverse also applies here and that is when you are purchasing material to be used as filling for for argument sake so when that soil comes to sight it is going to be in the bigger form in other words in the bulked form and you need to reduce it to the volume that it would be in its compacted form so let that be a lesson because every one of you are going to be caught in an exercise where the contractor present you with invoices for truck loads full of things whether that is for carting away or for purchasing material to come to site you cannot pay for the truck loads because it is the truck loads are in a bulked form in other words words it is like the soil on the side it is bigger than the soil required well when you're Excavating it's bigger but when you're filling the net quantity becomes smaller because it is going to be in its compacted form so when we talk about bulking in the built environment we are talking about how the volume of the soil increases when it gets excavated out of its compacted form okay and different types of soil have different bulking Factor is on the picture you can see the soil is quite dark so it is sort of a Turf and and that expansion will be much more because it has a a clay component to it that expansion is then much more than let's say a good red soil argument sake but the the type of the soil uh will be Illustrated in the geotechnical report and the information about the soil can be obtained from there to see what the bulking Factor would be okay but then just make a a a note that all measurements that we do are then the volume of the compacted soil okay then the first measur measurable Clause there comes Under The Heading of site clearance and you will see the description on the left hand side of the measurable item is digging up and removal of rubbish debris vegetation Hedges shrubs and trees not exceeding 200 mm girth Bush Etc and it gives the unit of measurement as square meters and then in the measurement rules it says where the value is of relative significance the removal of Hedges Etc shall be given separately in meters or in number okay so at this point I just want to jump to the next two slides where I want to illustrate to you how we would go about measuring the square meters of site clearance now remember all these items that are described over here as you get to a site that hasn't been developed before and you can see it is overgrown and there are all kinds of things and now you need to prepare your site to start your uh building excavations and so on so the first practical thing we do is we go to the footprint of the building and we measure it 1.5 M past the footprint of the building and this 1.5 when I was a student where you are now the lecturer said to me we use 1 5 this is a rule that is not written anywhere but this is commonly accepted in the bolt environment because all of us have been taught that way so let me just go to the next slide over there and I have a footprint of the building where you can see the solid line that depicts the the building and I have a dotted line over there and this distance over here is the 1.5 so so if you can imagine then that what you really need to do your building is on the solid line but you need space to get in to do the the actual construction of your building so we are adding 1.5 and we're making the footprint of the site clearance bigger than the building itself okay very rarely will you be required to clear an entire site because your building is is not the size of the entire site of course it is possible if you have a very small site and we will do an example in the course of the Year where we are actually going to do that but the the the run-of the- mill item is this 1.5 rule where we are adding 1.5 to either sides of the footprint of our building and we are creating a space larger than our building for our site clearance okay that then let me just go back to the description that then pertains to everything that is included this in this description as well as trees not exceeding 200 mm girth now let me just move on to the next Clause over there that deals with trees and I will get back to the Hedge in a moment I just want to do the trees quickly so there it says remover of larger trees um and tree stumps exceeding 1 meter high exceeding 1 meter high and I will explain the 1 meter in a moment and then on the measurement rules and that is measurement rule 6 and S it goes on and it says the girth around the trunk one meter above the level shall be stated grouped in sizes exceeding 200 mm and not exceeding 500 mm and thereafter in stages of 500 mm so let me just jump a few slides forward for the explanation so you get to your site and there are a number of trees that are interfering with where the building needs to be built so 4 1 M high from your natural ground level Illustrated over there so in other words in that position you are going to measure around the tree trunk all the way all the way around actually my arrow couldn't go all the way around with the little figure that I used so the girth means all around the trunk not the diameter of the trunk all the way around the trunk so the small trees with a girth of more than 200 m MERS is included with the square meter measure but the moment a tree is more than 200 so you're measuring around this tree and you see okay I am somewhere argument sake let's say that I've measured it now and this is 300 so you will go around the site and you will measure all the trees that need to be removed and now the sit the standard system says to us all the trees where you have measured the trunk between 200 right up to 500 will all be given together so you're going to measure measure measure all those trees see if they fall in between 200 and 500 mm girth and then you will add them there together but the very large trees might have a girth of much bigger than that then standard system comes along and it it says therea uh in stages of 500 millim so that means your next stage is going to be a 500 to 1 M and the next stage thereafter is going to be 1 M to 1.5 M girth so you will go all around and it is good practice for for the Design Consultants to actually mark up the trees so this is as part of preparation of your bill of quantities you will definitely go to the site and go and see and in today's era where the environment is very important large trees will not be taken out unnecessarily so the trees that will need to be removed must uh impact on your building somehow otherwise it won't be necessary to remove them okay let me jump then back to the to the Clause that I was dealing with over here then just getting back to the hedges of significance um sometimes you find Hedges where Hedges have actually been grown and trimmed to form a fence or something like that so that would be of significance it's not just a small little hedge over there so you will measure that separately then and depending on what the size of it is you will decide whether you will do that in linear meters or whether you will do that in numbers okay so the important thing to remember over here is that the small trees are up to 200 girth are included in the square meters and then the larger trees uh are measured in Number the removal of the larger trees is is measured in number uh the reason for that is that the removal of trees is quite an expensive exercise and now one thing that I haven't said is that when you are removing the trees the standard system also requires you to State whether the roots need to be removed or not so let's say argument sake that tree is sitting inside the footprint of your building so you can't just cut it off and and and leave what's under the ground there because that will will rot with time which means that a hole might be able to form there where you are so that is important that you that you actually state that and depending also on the type of the tree the hole created by removing the roots it depends on the the root system of the tree how big that hole will be uh to be backfolded and so on so measurement rule number seven there in the standard system then says the scriptions shall State whether the roots are to be grabbed up and the holes filled in stating the method and or the degree of compaction so we'll get to the compaction when we do the filling item but uh just know that when you're measuring this item it is all inclusive item and it must be stated in the description of removing the tree okay then when you are dealing with tree stumps that are um higher than a meter you deal with them exactly the same way as you would be dealing with a tree and if it is a stump not exceeding 1 M you will measure the girth of it at the at the top of the the stump which might not necessarily be one meter above the ground as required for a tree or a larger stump okay so whenever you get to a drawing this will be your first measurable item you've got to prepare the site before you can actually start with the execution of your building right I've dealt with that and with that so our next heading over there is excavation filling Etc uh and that is the Clause four over there deals with the nature of the material to be excavated in now you might have heard me often say excavate in Earth now that would be the default description that we are going to use now the nature of the soil and I have listed something over here it can either be sandy soil if you are close to a river or a beach or it can be clay soil or it can be Turf etc etc but we don't say excavate in sandy soil or excavate in clay or excavate in Turf we say excavate in Earth because all of those fall in the category of Earth so if you do not have a geotechnical report that you can attach to your bll of quantities you must give an indic a in your descriptions as to what kind of soil is on the site but if the contractor goes to site in preparation for his tender he will obviously also be able to identify the kind of soil that he can be um um expecting but in most cases every piece of land has a geotechnical report and it is preferable that the geotechnical report must be attached to the bll of quantities so that the contractor has a good idea of what kind of soil there is and how his sight has been described okay so that deals with the nature of the material okay then we get to oh I don't want to do this illustration yet so let me just skip over this clause for a moment uh now the Clause the next Clause over there talks about the classification of the material to be excavated and in measurement rule number 11 and number 12 basically it just says excavations shall be described to be in the type of material that is the least difficult to excavate and then in 12 it says excavations in material of a more difficult nature shall be suitably Des classified and given as extra over now people this little sentence is very loaded I'm going to explain different concepts to you over here but let me just finish read reading that little sentence over there and then it says separating only bulk and trenches and holes I want you to go and specifically look at this because it shows the trenches and holes in inverted brackets the moment the standard system does that it means that it wants you to measure those items together as one concept trenches and holes so when I'm doing the actual excavation I want to measure trenches and holes separately from each other because trenches will are long strips and they can easily be excavated with the mechanical excavator as you saw on the picture on the first slide where holes are square and they are for columns argument sake so those will be excavated they cannot be excavated by a mechanical excavator if it is a small hole of one by one and it will be excavated by hand okay but now first of all I want to get back to this description of least difficult material so that is what we described then as excavate in Earth so from the previous slides then the s soil the the turf the clay soil whatever that is the easiest you can easy excavate it and you can use a shovel to do that very easy to do that then the second Clause says when it becomes more difficult to excavate it you must measure it as extra over and now here is a very very important concept and it's the first time you are being faced with it so if I go to my little illustration at the bottom over here so my first Clause is what I am illustrating in the blue now this is the volume that I'm going to measure the entire volume of my excavation I am going to measure in the first item then in the second item and this is this what I'm trying to illustrate over here is that to the bottom of this excavation here we encounter some r Rock now the geotechnical report will tell you more or less what rock you can expect to find on the site it would argument sake say say there will be uh 1 percentage of your excavation can be hard rock and 2% or 5% will be soft rock but our standard system doesn't say anything about hard rock or soft truck it just says material least difficult and material more difficult to excavate so here on the left hand side of the slide you can see I have a clip that comes out of the general preambles for trades and it also starts off by saying classification of material and here you can see the terminology that I've been using of hard rock soft rock and Earth so Earth is the least difficult so so when we do the Earth we do the entire volume then we go to our concept of extra over now the extra over is an indication that we are deviating from our rule of net measure and it means that in exactly the same position as I have measured the earth I am coming to measure the more difficult material so I will say 1% of the total volume will represent argument sack the Hard Rock and I will measure that as extra over because I have already measured the entire volume okay this concept of extra over comes a few times in the standard system but if you don't grasp it 100% now you will see when we do the practical application how this comes but just know that the least difficult material is Earth and the more difficult material materal is Hard Rock and soft rock and for us to be able to distinguish between what is Earth what is soft rock and what is Hard Rock we default back to our specification document and we go and see there and you can go and read these descriptions of the Hard Rock and the soft rock and you will see that the excavation in Earth is material that you can do by with with not too much much force when you are doing soft rock excavation it requires pneumatic tools like a jackhammer for instance because you need to break up that material it can't just be taken out with a pick and a shovel and then when you are doing hard rock material this is now really really hard and there are examples in the a specification document that says this is granite quartsite sandstone uh or rock and what you need there is you need to either move it by splitting it or by blasting it in other words you're going to use explosive materials to break this to be able to to actually take that out of the excavation now what happens when we're dealing with a small excavations and let me just for a moment I want to clear the slide so I'm just going backwards and forwards again so that I just have a clean slate so what would typically happen let's say argument sake that this rock that we found over here was all the way through like that but the indication was that you you are going to excavate argument say 600 mm and now when you hit this Bedrock over here we are on 4 mm 4 100 mm at least so if your rock is continuous there's no sense for a simple excavation to now go remove that rock because the whole intention of Excavating is so that you get to a solid area that is strong enough to carry your foundations and rock is strong so it's only when it is partial rock that it would actually be removed from the excavation because the the the bit on the side of the partial rock is still not strong enough to carry our excavation okay so when you are dealing then with the classification know that we measure the least difficult for the full volume and the extra over only for partial of the volume and again here it will be an educated guess that comes from the geotechnical report in terms of a a percentage and then when the reality happens you will go to site and you will measure the volume of That Rock with the tape measure so that you can correct your measure okay so I just want to get back to this slide and I want to just illustrate again so the volume that you are taking out of here so that is your Excavating Earth you are placing the volume over there and although the Heap increases in volume we are sticking to the volume that we have excavated over there so this Heap that goes on the side over here can be used for several stuff because the way we are going to measure we have now measured an excavation the next item we are going to put in there is going to be our concrete then we are going to construct a wall on top of that and then we are going to take from this Heap and we're going to do the back filling on the sides of the walls like that okay now at the moment moment I am dealing with the excavations I'm not dealing with the fillings yet uh I will deal with filling in the next session but just know that this Heap Lies over there and the first action of excavation and placing comes with excavations and the next action of retrieving from the Heap and using it as filling is then a separately measurable item and then ultimately this Heap that we are placing over here we need to use the net volume of that Heap again for something so either for filling or for cutting away and those two items are separately measurable items but we will get to them when time comes okay so just know that now we are dealing with the excavation and the placing right then in the excavation we are going to have three types of excavations the first one is what we are going to deal with mostly in this subject and that is the small excav ations like for trenches and holes and these are small designed shapes so we are going to measure exactly according to the shape then the second category is bulk excavations that would typically be something like a basement excavation so it's a deep and a large excavation but it is still a designed shape then the third type of excavation is what we refer to as openface excavations now open face is exactly that it is all over the site and this is typically used and here I have Illustrated where you have a sloping site like this and you want to place a building so it is awkward to to have a building on a slope like that so you're going to change the shape of the site to suit your building to do something like that so you're going to create a platform so the alternative of creating a platform is to have steps inside your building so if you don't deliberately want steps let's say we have a house and it is a single story it is all on one story so steps take space in your house so do you want to shape your site or is the slope of your site slim enough so that you can get away with a few steps instead of losing so the the offset is always going to be are you going to shape your site or are you going to do steps in your building now the the design Consultants need to decide where the um Optimum point of design is because to move soil around and to cut that excavated soil off from away from sight is a very expensive exercise so open face is normally then um associated with large complex buildings let's say arguments like like a shopping center where the the ground floor all W to be on one level Etc okay right so let's look at the excavation Clause itself and starting off then with the um the unit of measurement excavations are measured in cubic meters and in the description of the excavation it talks about B bulk excavations trenches holes and see that those aren't in inverted brackets I want you to go back to the the the Clause of the Excavating in more difficult material there you can see trenches and holes in inverted brackets but when we are measuring the excavation we want to measure those separately for the reasons I gave just now because your method of excavation for trenches and holes and bulk excavations are different so each one of those are are going to be given separately and then the standard system requires us to give this excavation in successive depths of 2 m now let me just jump to the next slide to explain that so let's say argument sake here I have an excavation that is 7 and 1/2 M deep that would mean I'm going to go all the way down to that level over there so you can see the way that I have notated on the drawing I've got a 2 m and then another 2 m which takes me up to 4 M deep and then another 2 m that takes me up to 6 M deep and another 2 m that takes me up to 8 m deep so the standard system wants us to split this excavation in stadia successive depths of 2 m so if I have a 7 and 1 half meter deep excavation that means that uh people I see a lot of you coming in you're most welcome I am almost finished with this lecture I'm running slightly late so the tag will be available for you I suggest that you rather leave at this stage and uh watch the video on the general instructions then to continue here because I am right at the end of this lecture and it won't make sense to you now but okay let me just keep explain but you're welcome to stay if you want to so what happens over here is the successive depth so let me just get I've got a 7 and 1/2 M deep so that means I'm going to measure for a 7 and 1/2 M deep I'm going to measure 1 2 [Music] 3 four excavation items because that's what the rule requires of me so I'm going to say excavate in trenches not exceeding 2 m deep then will say Excavating trenches exceeding 2 m not exceeding 4 M deep then the third one exceeding 4 m not exceeding 6 M deep and so I keep going the last one I will say exceeding six not exceeding 8 m deep I stick to my rule in the standard system and I say not exceeding 8 m although my 7 and 1/2 m is shorter that just means that it is somewhere shorter of the 8 m but I'd still describe it as 6 to 8 m deep now the relevance of this is that the first category can be measured by hand because 2 m uh the the average man is about 1.7 1.8 m tall so the 2 m is just just just above his head so it's possible for a man to stand here and to Turf the material onto the surface but it's not possible for him to stand over here and turf it onto the surface neither over here or even going deeper so the cue over here is that this material can be excavated by hand or by a machine but the deeper ones definitely by machine and then for the excavation definitely we are chopping the excavations as they go along and that's what it means to measure in successive depths of 2 m okay then the third requirement over here it says that the separation of the depths must be relative to the original level or the reduced ground level so we will be saying excava in Earth not exceeding 2 m deep below natural ground level argument sake and then we can also have the cases where we have a very deep BAS excavation but at the bottom of the excavation which is argument sa already 8 m down there you now want to do a smaller excavation for columns or strip footings or something and then you will say that it is not exceeding 2 m deep below reduced ground level because you can't now say that that is an excavation uh exceeding eight and not exceeding 10 MERS deep because that doesn't give the real picture the big excavation is already done and you're doing a smaller excavation inside of that trench okay then the standard system goes ahead and it says that open face excavations remember now we said that the three types is the bulk the trenches and holes or the open face it says for open face excavations you don't have to separate the working depths so if you can imagine what would happen Happ on a site think about the plant that I have referred to now for small excavations trenches or holes it's possible to do it by hand or with a back actor which is a small plant but when you're doing openface excavations and you're moving a lot of material around you will be using a a bulldozer those big scraping machineries that you see when they're doing either earth works for roads or on sites or so on so it's a very big machine and it moves a lot of soil at the same time so it's not necessary there in that application and it is it is it remains on the surface because you are shaping your site over there and that is that is what that um why it is not necessary to State the overall depths over there okay I've already explained this slide over here so let me just then stop with a a typical example so we have now talked about what we are Excavating in from which level we are Excavating sorry what we are Excavating for what we are Excavating in and how deep we want to excavate so for every single excavation item we are going to measure these four facts must be given so you're going to say you're Excavating in Earth four trenches not exceeding 2 m or if that was exceeding two not exceeding 4 M so whatever the rule is that you're replying you must state it over there and then the last one is from which level are you Excavating the order of these items in your description aren't overly important just as long as you have all four the facts over there okay then continue in with the measurement rules of clause six over there uh the number six 6.6 of the excavation gives another item that says digging up top soil to be preserved this is one of those exceptional items that is measured in square meters and not in cubic meters what the idea behind this item is is that it is to strip the top soil because the top soil is the earth that that uh is um fertile vegetation in which things grow the deeper you excavate you don't see plants in deep excavated areas so here you're only going to strip the top off so the moment you are measuring in square meters you need to give a third dimension so you're going to in your description State how deep you're going to strip are you stripping for 100 mm are you stripping for 150 mm or whatever the side the situation is and then you are going to state where you are setting it aside the 100 m comes from that placing situation and if you look at the third column or the fourth column in the standard system it says there that setting aside excavated material within 100 m from the perimeter of the excavation for the use as filling forming Etc so that is a requirement of the standard system the moment you cannot set that in that area then it becomes an additional measurable item and that goes about the carting on or the carting away of material so in most sites it is possible because 100 m is is is is as long as a ragby field so the chance that the the footprint of your building is so big that you don't have a space to put your soil is basically uh very slim so all I want to say further on about the stripping of the top soil and of um other material the idea of stripping of the top soil is that it gets preserved and that it gets placed back later on to use for planting Etc so that means that the Heap that this top soil is going to lie on needs to be protected so that it doesn't get contaminated with other excavated material because the other excavated material might be dead material that can't be used for landscaping so definitely this material is then for later use and if it does get contaminated that means that at the cost of the contractor he will split that material out again which means that you need to sift the material at a at a a cost to the contractor okay then I've already read out the Clause where I say that the setting aside of the material is um deemed to be included and the the deem to be included is uh bracketed by the 100 meters that I have just explained and then the last point over there that I want to deal with is that the net void of the drawing and this goes back to our principle of uh net quantities so if your excavation is like that and on your drawing whatever is Illustrated over here that is what you're going to measure to whether this is 600 or whether this is 900 or whether what that width is that is what is meant by the net void as per drawing now to the construction management students I want to tell you that very quickly errors happen so what you should do is when you send the back actor out there to go or before you send the back actor out there to go and do the excavation just take check the size of the toe because standard excavations come in 450 500 6 00 650 750 700 and it might sound like a little bit to you but if you start measuring this strip any wider even if it's 50 mm 50 mm on a considerable depth and a considerable length becomes quite a lot of cubic meters and you will not get paid for that you will only get paid for what is demonstrated on your drawing okay so that is what the net void refers to then watch is on your design drawing okay and the last slide over here I have put a little example for you there and at this point I want you to think for yourselves based on the lecture how you would be measuring that trench excavation and I will put the solution on clickup a little bit later I want you to think about this first okay so that wraps up this lecture then and the complete uh recording will then be available on clickup

okay in this session we&#39;re starting with the interesting work and this is where the rules are coming in to be applicable directly to drawings so as we go along you must visualize things that you have been exposed to in arguments act the drawing subject or in the uh Building Technology module and so on and together with uh visualizing something you must also bear in mind any item where the action required impacts on the cost the moment that happens it is a separately measurable item so the slide that is on your screen at the moment you will see on the left hand side there I have a a shovel and on the right hand side there is a mechanical excavator so what is the importance of this and that is sometimes clients and specifically government clients want to restrict the use of um mechanical excavators because they want to create extra work so they will make a project subject to what we call Labor intensiveness so they can say that I want this project of mine to all be excavated by hand but it is not always possible to excavate everything by hand because the deeper the excavation goes uh it becomes impossible for a man standing in argument sake an excavation 3 MERS deep to Turf the soil out onto the surface so also there then uh there will have to be a distinction between how we go about these things but the type of projects where government makes this uh applicable are of course then uh simpler in nature where it is possible to excavate by hand okay so again I&#39;m emphasizing anything that impacts on the price must be given separately so it&#39;s possible that you can be involved in a project where you have hand excavation and machine excavation and then you will have to uh set them separately so that the contractor can price them appropriately okay so let&#39;s look at the first Clause over there and this is a a general the heading over there is and the first Clause is Method and procedure so the moment there is a general Clause like this it means that this General Clause applies to all the other Clauses in this specific trade so let&#39;s see what is happening there on the method and procedure so the first bullet point that I have over there and if you have a standard system next to you or open you can jump there and you can see that these are actually the measurement rules that are in the second column over there so it says restrictions regarding blasting jackhammers mechanical excavators compactors Etc so the moment the contract is a restriction is put on a contractor where he cannot use any one of these pieces of plants or where he&#39;s only allowed to use his Jackhammer after hours arguments act because of noise any restriction like that must be listed in your stand in your bill of quantities otherwise the contractor will not be able to price properly okay then the second point over there the excavation or filling in a particular order as I said just now there are few exceptions to the rule but if this exception does apply it must be specifically stated um otherwise the pricing is going to be the general rule which would then be incorrect okay and the third point over there uh revolves around multiple handling and the specific Clause says prescribed multiple handling of material shall be included in the descriptions now let me explain to you the concept of multiple handling so on the on the next slide over here I have a a little diagram so what that is meant to illustrate is you have a site and you have column bases and between the column bases you have strip footings so if I can just get my pencil going over here so this is your site boundary these are your column bases and this is then your strip footing in between so when the contractor gets to sight he has an open sight he needs to put set out his columns and he needs to dig the columns so what happens is he&#39;s digging away so he&#39;s dug a hole so this material that comes out here needs to be placed on the surface somewhere and is going to dig as you can see nine holes on this site over here but what now happens if he starts on the first row over there and he puts this material that he is digging over here argument sake he puts it over there now when he wants to dig those two bases he needs to remove the Heap of soil and argument sake put it over there so that is very bad planning if there is space to put the material the contractor must put the material where it doesn&#39;t interfere with any other work so the the multiple handling that I&#39;m talking about so when we&#39;re doing an excavation item the Excavating and placing of the excavated material on the surface is one item it is covered in one item so that material cannot be placed over here where a strip needs to be excavated or over here or over there argument sake or anywhere in the way the best place to place it would be over here or over here where it doesn&#39;t interfere with the rest of the excavations but now it is possible that you don&#39;t have a nice site like this where you have place to put that material let&#39;s say it is a confined space uh it&#39;s a site in the CBD of Petoria and you&#39;re digging in between two other buildings there simply isn&#39;t any space so the engineer or the architect will come and say to the contractor okay do your whole excavations and place the material where you can place it and then before you do the strip footings I will allow you to cart that material away and go and put it somewhere else because here is no place on your site and in that instance that is what we refer to as multiple handling because the norm is we excavate and place on the surface in one item the next item we will take from the surface and use that material for filling is the second item and if any material is left over we will take that material and cart it away from sight or we will spread it over sight or whatever we will do with that soil but the multiple handling comes in where placing is not possible um and it interferes with the rest of the work so that material needs to be handled once or twice so it&#39;s it&#39;s placed on the surface first of all and then it&#39;s removed somewhere else and in that case moving this the second soil is the multiple handling so the second action of taking the soil and moving it somewhere else to another site or somewhere outside of the site where it can be preserved for later use that is the second action and that is what we refer to as multiple handling so the first action is taking it out and placing it on the surface normally the second action would be taking it from the surface and using it for filling or something else which is a separately measurable item but if the second action is taking it and moving it somewhere else but not using it for filling that is the multiple handling okay and if that is the case due to the site conditions then the contractor is entitled to payment for it if multiple handling is caused due to his bad planning he pays for it okay but if it is required due to the a restricted site or something it must be specifically stated and the contractor will be paid for it okay the second Clause under General is bulking and the description says no allowance shall be made in measurements of disposal or cting away of material for bulking so I want you to look at this picture on this slide and you can see there is a very slim excavation over there but next to the excavation there&#39;s a huge heap of soil lying over there so that that already gives you an idea of what we are talking about that swell in its compacted form is smaller than swell in uncompacted form so our principle of net measure is soil is always measured in the compacted form so when I&#39;m measuring that excavation that you see there on the slide I will literally be measuring the length of it the width of it as you see on the slide and the depth of it as you see on the slide and the moment it gets out over there um it is larger so the inverse also applies here and that is when you are purchasing material to be used as filling for for argument sake so when that soil comes to sight it is going to be in the bigger form in other words in the bulked form and you need to reduce it to the volume that it would be in its compacted form so let that be a lesson because every one of you are going to be caught in an exercise where the contractor present you with invoices for truck loads full of things whether that is for carting away or for purchasing material to come to site you cannot pay for the truck loads because it is the truck loads are in a bulked form in other words words it is like the soil on the side it is bigger than the soil required well when you&#39;re Excavating it&#39;s bigger but when you&#39;re filling the net quantity becomes smaller because it is going to be in its compacted form so when we talk about bulking in the built environment we are talking about how the volume of the soil increases when it gets excavated out of its compacted form okay and different types of soil have different bulking Factor is on the picture you can see the soil is quite dark so it is sort of a Turf and and that expansion will be much more because it has a a clay component to it that expansion is then much more than let&#39;s say a good red soil argument sake but the the type of the soil uh will be Illustrated in the geotechnical report and the information about the soil can be obtained from there to see what the bulking Factor would be okay but then just make a a a note that all measurements that we do are then the volume of the compacted soil okay then the first measur measurable Clause there comes Under The Heading of site clearance and you will see the description on the left hand side of the measurable item is digging up and removal of rubbish debris vegetation Hedges shrubs and trees not exceeding 200 mm girth Bush Etc and it gives the unit of measurement as square meters and then in the measurement rules it says where the value is of relative significance the removal of Hedges Etc shall be given separately in meters or in number okay so at this point I just want to jump to the next two slides where I want to illustrate to you how we would go about measuring the square meters of site clearance now remember all these items that are described over here as you get to a site that hasn&#39;t been developed before and you can see it is overgrown and there are all kinds of things and now you need to prepare your site to start your uh building excavations and so on so the first practical thing we do is we go to the footprint of the building and we measure it 1.5 M past the footprint of the building and this 1.5 when I was a student where you are now the lecturer said to me we use 1 5 this is a rule that is not written anywhere but this is commonly accepted in the bolt environment because all of us have been taught that way so let me just go to the next slide over there and I have a footprint of the building where you can see the solid line that depicts the the building and I have a dotted line over there and this distance over here is the 1.5 so so if you can imagine then that what you really need to do your building is on the solid line but you need space to get in to do the the actual construction of your building so we are adding 1.5 and we&#39;re making the footprint of the site clearance bigger than the building itself okay very rarely will you be required to clear an entire site because your building is is not the size of the entire site of course it is possible if you have a very small site and we will do an example in the course of the Year where we are actually going to do that but the the the run-of the- mill item is this 1.5 rule where we are adding 1.5 to either sides of the footprint of our building and we are creating a space larger than our building for our site clearance okay that then let me just go back to the description that then pertains to everything that is included this in this description as well as trees not exceeding 200 mm girth now let me just move on to the next Clause over there that deals with trees and I will get back to the Hedge in a moment I just want to do the trees quickly so there it says remover of larger trees um and tree stumps exceeding 1 meter high exceeding 1 meter high and I will explain the 1 meter in a moment and then on the measurement rules and that is measurement rule 6 and S it goes on and it says the girth around the trunk one meter above the level shall be stated grouped in sizes exceeding 200 mm and not exceeding 500 mm and thereafter in stages of 500 mm so let me just jump a few slides forward for the explanation so you get to your site and there are a number of trees that are interfering with where the building needs to be built so 4 1 M high from your natural ground level Illustrated over there so in other words in that position you are going to measure around the tree trunk all the way all the way around actually my arrow couldn&#39;t go all the way around with the little figure that I used so the girth means all around the trunk not the diameter of the trunk all the way around the trunk so the small trees with a girth of more than 200 m MERS is included with the square meter measure but the moment a tree is more than 200 so you&#39;re measuring around this tree and you see okay I am somewhere argument sake let&#39;s say that I&#39;ve measured it now and this is 300 so you will go around the site and you will measure all the trees that need to be removed and now the sit the standard system says to us all the trees where you have measured the trunk between 200 right up to 500 will all be given together so you&#39;re going to measure measure measure all those trees see if they fall in between 200 and 500 mm girth and then you will add them there together but the very large trees might have a girth of much bigger than that then standard system comes along and it it says therea uh in stages of 500 millim so that means your next stage is going to be a 500 to 1 M and the next stage thereafter is going to be 1 M to 1.5 M girth so you will go all around and it is good practice for for the Design Consultants to actually mark up the trees so this is as part of preparation of your bill of quantities you will definitely go to the site and go and see and in today&#39;s era where the environment is very important large trees will not be taken out unnecessarily so the trees that will need to be removed must uh impact on your building somehow otherwise it won&#39;t be necessary to remove them okay let me jump then back to the to the Clause that I was dealing with over here then just getting back to the hedges of significance um sometimes you find Hedges where Hedges have actually been grown and trimmed to form a fence or something like that so that would be of significance it&#39;s not just a small little hedge over there so you will measure that separately then and depending on what the size of it is you will decide whether you will do that in linear meters or whether you will do that in numbers okay so the important thing to remember over here is that the small trees are up to 200 girth are included in the square meters and then the larger trees uh are measured in Number the removal of the larger trees is is measured in number uh the reason for that is that the removal of trees is quite an expensive exercise and now one thing that I haven&#39;t said is that when you are removing the trees the standard system also requires you to State whether the roots need to be removed or not so let&#39;s say argument sake that tree is sitting inside the footprint of your building so you can&#39;t just cut it off and and and leave what&#39;s under the ground there because that will will rot with time which means that a hole might be able to form there where you are so that is important that you that you actually state that and depending also on the type of the tree the hole created by removing the roots it depends on the the root system of the tree how big that hole will be uh to be backfolded and so on so measurement rule number seven there in the standard system then says the scriptions shall State whether the roots are to be grabbed up and the holes filled in stating the method and or the degree of compaction so we&#39;ll get to the compaction when we do the filling item but uh just know that when you&#39;re measuring this item it is all inclusive item and it must be stated in the description of removing the tree okay then when you are dealing with tree stumps that are um higher than a meter you deal with them exactly the same way as you would be dealing with a tree and if it is a stump not exceeding 1 M you will measure the girth of it at the at the top of the the stump which might not necessarily be one meter above the ground as required for a tree or a larger stump okay so whenever you get to a drawing this will be your first measurable item you&#39;ve got to prepare the site before you can actually start with the execution of your building right I&#39;ve dealt with that and with that so our next heading over there is excavation filling Etc uh and that is the Clause four over there deals with the nature of the material to be excavated in now you might have heard me often say excavate in Earth now that would be the default description that we are going to use now the nature of the soil and I have listed something over here it can either be sandy soil if you are close to a river or a beach or it can be clay soil or it can be Turf etc etc but we don&#39;t say excavate in sandy soil or excavate in clay or excavate in Turf we say excavate in Earth because all of those fall in the category of Earth so if you do not have a geotechnical report that you can attach to your bll of quantities you must give an indic a in your descriptions as to what kind of soil is on the site but if the contractor goes to site in preparation for his tender he will obviously also be able to identify the kind of soil that he can be um um expecting but in most cases every piece of land has a geotechnical report and it is preferable that the geotechnical report must be attached to the bll of quantities so that the contractor has a good idea of what kind of soil there is and how his sight has been described okay so that deals with the nature of the material okay then we get to oh I don&#39;t want to do this illustration yet so let me just skip over this clause for a moment uh now the Clause the next Clause over there talks about the classification of the material to be excavated and in measurement rule number 11 and number 12 basically it just says excavations shall be described to be in the type of material that is the least difficult to excavate and then in 12 it says excavations in material of a more difficult nature shall be suitably Des classified and given as extra over now people this little sentence is very loaded I&#39;m going to explain different concepts to you over here but let me just finish read reading that little sentence over there and then it says separating only bulk and trenches and holes I want you to go and specifically look at this because it shows the trenches and holes in inverted brackets the moment the standard system does that it means that it wants you to measure those items together as one concept trenches and holes so when I&#39;m doing the actual excavation I want to measure trenches and holes separately from each other because trenches will are long strips and they can easily be excavated with the mechanical excavator as you saw on the picture on the first slide where holes are square and they are for columns argument sake so those will be excavated they cannot be excavated by a mechanical excavator if it is a small hole of one by one and it will be excavated by hand okay but now first of all I want to get back to this description of least difficult material so that is what we described then as excavate in Earth so from the previous slides then the s soil the the turf the clay soil whatever that is the easiest you can easy excavate it and you can use a shovel to do that very easy to do that then the second Clause says when it becomes more difficult to excavate it you must measure it as extra over and now here is a very very important concept and it&#39;s the first time you are being faced with it so if I go to my little illustration at the bottom over here so my first Clause is what I am illustrating in the blue now this is the volume that I&#39;m going to measure the entire volume of my excavation I am going to measure in the first item then in the second item and this is this what I&#39;m trying to illustrate over here is that to the bottom of this excavation here we encounter some r Rock now the geotechnical report will tell you more or less what rock you can expect to find on the site it would argument sake say say there will be uh 1 percentage of your excavation can be hard rock and 2% or 5% will be soft rock but our standard system doesn&#39;t say anything about hard rock or soft truck it just says material least difficult and material more difficult to excavate so here on the left hand side of the slide you can see I have a clip that comes out of the general preambles for trades and it also starts off by saying classification of material and here you can see the terminology that I&#39;ve been using of hard rock soft rock and Earth so Earth is the least difficult so so when we do the Earth we do the entire volume then we go to our concept of extra over now the extra over is an indication that we are deviating from our rule of net measure and it means that in exactly the same position as I have measured the earth I am coming to measure the more difficult material so I will say 1% of the total volume will represent argument sack the Hard Rock and I will measure that as extra over because I have already measured the entire volume okay this concept of extra over comes a few times in the standard system but if you don&#39;t grasp it 100% now you will see when we do the practical application how this comes but just know that the least difficult material is Earth and the more difficult material materal is Hard Rock and soft rock and for us to be able to distinguish between what is Earth what is soft rock and what is Hard Rock we default back to our specification document and we go and see there and you can go and read these descriptions of the Hard Rock and the soft rock and you will see that the excavation in Earth is material that you can do by with with not too much much force when you are doing soft rock excavation it requires pneumatic tools like a jackhammer for instance because you need to break up that material it can&#39;t just be taken out with a pick and a shovel and then when you are doing hard rock material this is now really really hard and there are examples in the a specification document that says this is granite quartsite sandstone uh or rock and what you need there is you need to either move it by splitting it or by blasting it in other words you&#39;re going to use explosive materials to break this to be able to to actually take that out of the excavation now what happens when we&#39;re dealing with a small excavations and let me just for a moment I want to clear the slide so I&#39;m just going backwards and forwards again so that I just have a clean slate so what would typically happen let&#39;s say argument sake that this rock that we found over here was all the way through like that but the indication was that you you are going to excavate argument say 600 mm and now when you hit this Bedrock over here we are on 4 mm 4 100 mm at least so if your rock is continuous there&#39;s no sense for a simple excavation to now go remove that rock because the whole intention of Excavating is so that you get to a solid area that is strong enough to carry your foundations and rock is strong so it&#39;s only when it is partial rock that it would actually be removed from the excavation because the the the bit on the side of the partial rock is still not strong enough to carry our excavation okay so when you are dealing then with the classification know that we measure the least difficult for the full volume and the extra over only for partial of the volume and again here it will be an educated guess that comes from the geotechnical report in terms of a a percentage and then when the reality happens you will go to site and you will measure the volume of That Rock with the tape measure so that you can correct your measure okay so I just want to get back to this slide and I want to just illustrate again so the volume that you are taking out of here so that is your Excavating Earth you are placing the volume over there and although the Heap increases in volume we are sticking to the volume that we have excavated over there so this Heap that goes on the side over here can be used for several stuff because the way we are going to measure we have now measured an excavation the next item we are going to put in there is going to be our concrete then we are going to construct a wall on top of that and then we are going to take from this Heap and we&#39;re going to do the back filling on the sides of the walls like that okay now at the moment moment I am dealing with the excavations I&#39;m not dealing with the fillings yet uh I will deal with filling in the next session but just know that this Heap Lies over there and the first action of excavation and placing comes with excavations and the next action of retrieving from the Heap and using it as filling is then a separately measurable item and then ultimately this Heap that we are placing over here we need to use the net volume of that Heap again for something so either for filling or for cutting away and those two items are separately measurable items but we will get to them when time comes okay so just know that now we are dealing with the excavation and the placing right then in the excavation we are going to have three types of excavations the first one is what we are going to deal with mostly in this subject and that is the small excav ations like for trenches and holes and these are small designed shapes so we are going to measure exactly according to the shape then the second category is bulk excavations that would typically be something like a basement excavation so it&#39;s a deep and a large excavation but it is still a designed shape then the third type of excavation is what we refer to as openface excavations now open face is exactly that it is all over the site and this is typically used and here I have Illustrated where you have a sloping site like this and you want to place a building so it is awkward to to have a building on a slope like that so you&#39;re going to change the shape of the site to suit your building to do something like that so you&#39;re going to create a platform so the alternative of creating a platform is to have steps inside your building so if you don&#39;t deliberately want steps let&#39;s say we have a house and it is a single story it is all on one story so steps take space in your house so do you want to shape your site or is the slope of your site slim enough so that you can get away with a few steps instead of losing so the the offset is always going to be are you going to shape your site or are you going to do steps in your building now the the design Consultants need to decide where the um Optimum point of design is because to move soil around and to cut that excavated soil off from away from sight is a very expensive exercise so open face is normally then um associated with large complex buildings let&#39;s say arguments like like a shopping center where the the ground floor all W to be on one level Etc okay right so let&#39;s look at the excavation Clause itself and starting off then with the um the unit of measurement excavations are measured in cubic meters and in the description of the excavation it talks about B bulk excavations trenches holes and see that those aren&#39;t in inverted brackets I want you to go back to the the the Clause of the Excavating in more difficult material there you can see trenches and holes in inverted brackets but when we are measuring the excavation we want to measure those separately for the reasons I gave just now because your method of excavation for trenches and holes and bulk excavations are different so each one of those are are going to be given separately and then the standard system requires us to give this excavation in successive depths of 2 m now let me just jump to the next slide to explain that so let&#39;s say argument sake here I have an excavation that is 7 and 1/2 M deep that would mean I&#39;m going to go all the way down to that level over there so you can see the way that I have notated on the drawing I&#39;ve got a 2 m and then another 2 m which takes me up to 4 M deep and then another 2 m that takes me up to 6 M deep and another 2 m that takes me up to 8 m deep so the standard system wants us to split this excavation in stadia successive depths of 2 m so if I have a 7 and 1 half meter deep excavation that means that uh people I see a lot of you coming in you&#39;re most welcome I am almost finished with this lecture I&#39;m running slightly late so the tag will be available for you I suggest that you rather leave at this stage and uh watch the video on the general instructions then to continue here because I am right at the end of this lecture and it won&#39;t make sense to you now but okay let me just keep explain but you&#39;re welcome to stay if you want to so what happens over here is the successive depth so let me just get I&#39;ve got a 7 and 1/2 M deep so that means I&#39;m going to measure for a 7 and 1/2 M deep I&#39;m going to measure 1 2 [Music] 3 four excavation items because that&#39;s what the rule requires of me so I&#39;m going to say excavate in trenches not exceeding 2 m deep then will say Excavating trenches exceeding 2 m not exceeding 4 M deep then the third one exceeding 4 m not exceeding 6 M deep and so I keep going the last one I will say exceeding six not exceeding 8 m deep I stick to my rule in the standard system and I say not exceeding 8 m although my 7 and 1/2 m is shorter that just means that it is somewhere shorter of the 8 m but I&#39;d still describe it as 6 to 8 m deep now the relevance of this is that the first category can be measured by hand because 2 m uh the the average man is about 1.7 1.8 m tall so the 2 m is just just just above his head so it&#39;s possible for a man to stand here and to Turf the material onto the surface but it&#39;s not possible for him to stand over here and turf it onto the surface neither over here or even going deeper so the cue over here is that this material can be excavated by hand or by a machine but the deeper ones definitely by machine and then for the excavation definitely we are chopping the excavations as they go along and that&#39;s what it means to measure in successive depths of 2 m okay then the third requirement over here it says that the separation of the depths must be relative to the original level or the reduced ground level so we will be saying excava in Earth not exceeding 2 m deep below natural ground level argument sake and then we can also have the cases where we have a very deep BAS excavation but at the bottom of the excavation which is argument sa already 8 m down there you now want to do a smaller excavation for columns or strip footings or something and then you will say that it is not exceeding 2 m deep below reduced ground level because you can&#39;t now say that that is an excavation uh exceeding eight and not exceeding 10 MERS deep because that doesn&#39;t give the real picture the big excavation is already done and you&#39;re doing a smaller excavation inside of that trench okay then the standard system goes ahead and it says that open face excavations remember now we said that the three types is the bulk the trenches and holes or the open face it says for open face excavations you don&#39;t have to separate the working depths so if you can imagine what would happen Happ on a site think about the plant that I have referred to now for small excavations trenches or holes it&#39;s possible to do it by hand or with a back actor which is a small plant but when you&#39;re doing openface excavations and you&#39;re moving a lot of material around you will be using a a bulldozer those big scraping machineries that you see when they&#39;re doing either earth works for roads or on sites or so on so it&#39;s a very big machine and it moves a lot of soil at the same time so it&#39;s not necessary there in that application and it is it is it remains on the surface because you are shaping your site over there and that is that is what that um why it is not necessary to State the overall depths over there okay I&#39;ve already explained this slide over here so let me just then stop with a a typical example so we have now talked about what we are Excavating in from which level we are Excavating sorry what we are Excavating for what we are Excavating in and how deep we want to excavate so for every single excavation item we are going to measure these four facts must be given so you&#39;re going to say you&#39;re Excavating in Earth four trenches not exceeding 2 m or if that was exceeding two not exceeding 4 M so whatever the rule is that you&#39;re replying you must state it over there and then the last one is from which level are you Excavating the order of these items in your description aren&#39;t overly important just as long as you have all four the facts over there okay then continue in with the measurement rules of clause six over there uh the number six 6.6 of the excavation gives another item that says digging up top soil to be preserved this is one of those exceptional items that is measured in square meters and not in cubic meters what the idea behind this item is is that it is to strip the top soil because the top soil is the earth that that uh is um fertile vegetation in which things grow the deeper you excavate you don&#39;t see plants in deep excavated areas so here you&#39;re only going to strip the top off so the moment you are measuring in square meters you need to give a third dimension so you&#39;re going to in your description State how deep you&#39;re going to strip are you stripping for 100 mm are you stripping for 150 mm or whatever the side the situation is and then you are going to state where you are setting it aside the 100 m comes from that placing situation and if you look at the third column or the fourth column in the standard system it says there that setting aside excavated material within 100 m from the perimeter of the excavation for the use as filling forming Etc so that is a requirement of the standard system the moment you cannot set that in that area then it becomes an additional measurable item and that goes about the carting on or the carting away of material so in most sites it is possible because 100 m is is is is as long as a ragby field so the chance that the the footprint of your building is so big that you don&#39;t have a space to put your soil is basically uh very slim so all I want to say further on about the stripping of the top soil and of um other material the idea of stripping of the top soil is that it gets preserved and that it gets placed back later on to use for planting Etc so that means that the Heap that this top soil is going to lie on needs to be protected so that it doesn&#39;t get contaminated with other excavated material because the other excavated material might be dead material that can&#39;t be used for landscaping so definitely this material is then for later use and if it does get contaminated that means that at the cost of the contractor he will split that material out again which means that you need to sift the material at a at a a cost to the contractor okay then I&#39;ve already read out the Clause where I say that the setting aside of the material is um deemed to be included and the the deem to be included is uh bracketed by the 100 meters that I have just explained and then the last point over there that I want to deal with is that the net void of the drawing and this goes back to our principle of uh net quantities so if your excavation is like that and on your drawing whatever is Illustrated over here that is what you&#39;re going to measure to whether this is 600 or whether this is 900 or whether what that width is that is what is meant by the net void as per drawing now to the construction management students I want to tell you that very quickly errors happen so what you should do is when you send the back actor out there to go or before you send the back actor out there to go and do the excavation just take check the size of the toe because standard excavations come in 450 500 6 00 650 750 700 and it might sound like a little bit to you but if you start measuring this strip any wider even if it&#39;s 50 mm 50 mm on a considerable depth and a considerable length becomes quite a lot of cubic meters and you will not get paid for that you will only get paid for what is demonstrated on your drawing okay so that is what the net void refers to then watch is on your design drawing okay and the last slide over here I have put a little example for you there and at this point I want you to think for yourselves based on the lecture how you would be measuring that trench excavation and I will put the solution on clickup a little bit later I want you to think about this first okay so that wraps up this lecture then and the complete uh recording will then be available on clickup

Transcript for:Principles of Measurement in Construction Projects

Transcript for:
Principles of Measurement in Construction Projects