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CTC-275 Construction Methods Intro & Earthwork. Get SUNYIT email account.

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Presentation on theme: "CTC-275 Construction Methods Intro & Earthwork. Get SUNYIT email account."— Presentation transcript:

1 CTC-275 Construction Methods Intro & Earthwork

2 Get SUNYIT account

3 Many different ways to build same building How many ways can you build a ham and cheese sandwich? Types of ham, bread, cheese, toppings

4 Construction methods change when –Materials change Why thatch roofs? Why teepees and long houses? How important where nails to building –Equipment changes Horses to steam engines to today Erie Canal was dug with shovels and rock sleds Steam engines were stationary with belts going from pulleys to the engine

5 House Construction What materials can be used to build a house and what equipment is required –Wood – hammers, saws, drills, squares Can also use engineered wood What has happened to lumber in last 100 years? –Concrete – either cast in place, precast, or shotcrete Can be above ground or below –Steel –Stone –Brick –Adobe – only need forms –Haybales

6 House Construction Wooden houses can be constructed using three methods –1. Balloon Framing –2. Platform Frame –3. Modular – assembly line

7 Questions What made skyscrapers possible? How old is concrete and who first used it How old are nails?

8 Construction Order There is an order to all projects –What activities get done first –What activities need to be done in a specific order –What activities can be done at any point in time

9 Construction Order – Above ground Swimming pools Remove topsoil & level area 3’ larger that pool diameter Rake soil to remove rocks and roots Layout bottom track Dump sand inside pool area Level track Layout wall parts Roll wall and put on J channel and top rail Bolt wall, attach skimmer

10 Construction Order –Swimming pools Spread sand inside pool wall – rake & tamp Attach wall uprights Attach liner to J channel Use vacuum to suck liner to wall Plumb sand filter & pump together w/ skimmer & return line Attach top coping Add water Cut out skimmer and return

11 Construction Order Buildings: Clear site Foundation work Framing & Siding Roofing Windows and Doors Siding Electrical - rough Plumbing - rough Insulation Wall finishes

12 Construction Order Buildings: Foundation slab HVAC Ceilings Electrical – finish Plumbing – finish Paint/wall coverings Flooring Landscaping Pavement

13 Construction Order How far along do you need to be before starting next activity? On a house – probably one at a time On a 1 floor bldg – probably 1 activity at a time but depends on size Skyscraper – 1 activity per floor

14 Construction Order Highways Centerline survey Clearing Bridge work Centerline survey Earthwork to get to bottom of subbase elevation Centerline survey Subbase placement Centerline survey Base placement

15 Construction Order Highways Centerline survey Drainage Utilities (lights etc) Pavement base course Pavement wearing course Side slope grading Guard rail Lights and signs Pavement Markings

16 Construction Order Move from one end of project to the other with each activity Have multiple activities happening at any time Surveying is a full time activity

17 Start at beginning Earthwork –Moving rock or soil from one location to another –Processing it to meet location, elevation, density moisture content, etc –Efficient earthwork requires: accurate estimating of work quantities and conditions, proper equipment, competent job mangement

18 Equip Selection Proper equipment has major impact on efficiency and profitablility Can equipment perform required work Also look at profitablility, other uses for equipment, return on investment, availability of parts and services, effect of downtime on other construction equip

19 Equipment planning Need to plan to effectively use equipment Production of equipment –Production = Volume per cycle/cycles per hour –Cycles per hour is based on efficiency of equip Swing angle and elevation to truck bed Soil hardness and Soil type Room to manuever

20 Equipment planning Cost per production unit = equip cost per working hour/equip production per hour Table 2-1 show efficiencies

21 Soil And Rock General Soil Characteristics Trafficability – ability of soil to support weight of vehicles under repeated traffic –Controls traffic on unimproved access roads –Also gives measure of how earthmoving equip will operate –Primarily function of moisture conditions and soil type Loadability – how difficult to excavate and haul a soil –Granular – high –Compact cohesive - low

22 Soil And Rock Unit Soil Weight –Pounds /cy –Depends on soil type, moisture content, degree of compaction –Relation between soil weight and bearing capacity So soil weight is used as a measure of compaction Soil weight is also a factor in hauling

23 Soil And Rock Moisture Content(%) = (moist wt – dry wt)/dry wt X 100 Soil sample 120# Dry weight 100# MC = ( )/100X100 = 20%

24 Soil ID Boulders Cobbles – over 3” diameter Gravel 1/4” – 3” diameter Sand 0.7mm (200 sieve) – ¼” diameter Silt – 0.7 mm Clay less than 0.002mm Organic Matter decaying organic matter Soils classified using these types

25 Soil Classification Systems Unified System –All material 3’’+ removed –Separates soils into two main groups- Fine grained and coarse grained –Table 2-2, Figure 2-1 AASHTO System –7 classes of soil –Based on suitability of soil for subgrade –Table 2-3 –Table 2-4

26 Soil Volume Change Characteristics Soil Conditions –Bank – material in natural state before disturbance – Bank cubic yard –Loose – material that has been excavated or loaded loose cubic yard –Compacted – material after compaction compacted cubic yard

27 Soil Volume Change Characteristics Swell –Soil increases in volume when it is excavated Soil grains are loosened and air fills voids So 1 unit of soil in bank is smaller than the soil once it is excavated Swell(%) = ((weight/bank vol)/(weight/loose vol)- 1)X100 Soil wt = 2800#/cy in bank Soil wt = 2000#/cy loose Swell = ((2800/2000)-1)X100 = 40%

28 Soil Volume Change Characteristics Shrinkage –Soil decreases in volume when it is compacted Air is forced out of soil So 1 unit of soil compacted is smaller than the soil in the bank or once it is excavated Shrinkage(%) = (1-(weight/bank vol)/(weight/compacted vol))X100 Soil wt = 2800#/cy in bank Soil wt = 3500#/cy compacted Shrinkage = (1-(2800/3500))X100 = 20%

29 Soil Volume Change Characteristics Load and Shrinkage Factors –Need a common unit of measure for earthwork (get rid of calculations ) –Can use any of the three measures Called pay measure in contract Load factor = 1/(1+swell) –How many BCY can fit on a truck –LCY *Load Factor = BCY Shrinkage factor = 1- shrinkage How many BCY needed for CCY BCY * Shrinkage factor = CCY

30 Soil Volume Change Characteristics How many 10cy truck loads of soil = 1000CCY ? Swell = 30% Shrinkage = 25% BCY = CCY/(1-shrinkage) LCY = BCY*(1+Swell) LCY = CCY/(1-shrinkage)*(1+swell) LCY = 1000/(0.75)*1.30 = 1735 LCY Truck loads = LCY/10 = 174 truck loads

31 Spoil Banks Material removed from excavation –Longer than wide – spoil bank – triangular x section –Conical – spoil pile –To determine the size of the bank or pile need swell and angle of repose for soil –Angle of repose = angle that soil on side of bank naturally form Varies with moisture content and type Table 2-6

32 Spoil Banks Spoil bank –Vol = X sect area x length –B = (4V/(lx tan R))^1.2 –H = (B x tan R)/2 –B – base width –H height –L length –R angle of repose –V volume

33 Spoil Banks Spoil pile –Vol = 1/3  D/2)^2 X H –D = (7.64V/tan R)^1/3 –H = D/2 x tan R –D – diameter of base –H height –R angle of repose –V volume

34 –How long would a spoil bank for cy be if it was 100’ wide? Angle of repose = 30 deg –How high can a spoil pile 50’ in diameter be if the angle of repose = 35 deg? How many cy can it hold?

35 Estimating earthwork 3 types of excavations –Small pit –Trench –Large areas Roadways –Find cut and fill using cross sections –Mass diagram

36 Roadways

37 Estimating earthwork Pit Excavations –Area X average depth –Depending on size and ground may break into several geometric shapes to get volume –Give bank volume

38 Estimating earthwork Trench Excavations –V = x sectional area X length –Take x sections every 50 feet and compute volumes between x sections When estimating don’t forget the angle of repose and OSHA

39 Estimating earthwork Large Areas –Use a grid to find volume –V = A*(average depth) –For a rectangle –V = (LxW)(h1+h2+h3+h4)/4(1/27) cy

40 Estimating earthwork


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