Construction Technology 3

Transcription

1 Construction Technology 3 Assignment 2: Basement Construction Dr. Patrick Tang, School of Architecture and the Built Environment Michael Dernee C

2 Abstract: In the brief for the basement, there is the potential for rapid expansion. The Amazon highway is very close and noise pollution could affect the building s potential. Therefore the basement will be as low as possible allowing noise pollution to travel over the proposed building. Techniques will ensure that the least amount of energy will be needed to create the building and that the materials used will be long lasting to create not only an environmentally sustainable building but a physically sustainable building that will stand for many years.

3 Appendix: Title Page... i Abstract... ii Appendix... iii Physical... 1 Use... 1 Location... 1 Volume (horizontal)... 1 Clear site... 1 Volume (vertical)... 1 Type of soil... 2 Water table... 2 Disposal... 2 Mechanical... 3 Fixed... 3 Moving... 3 Transport system... 4 Excavation lateral support system... 5 Ground water control... 6 Foundation... 7 Shallow foundation... 7 Deep footings... 7 Basement method... 8 Slab... 8 Waterproof membrane... 9 Drainage Columns Suspended slab Cost analysis Pictorial explanation Conclusion Bibliography... 18

4 Physical: Use Basement allocation: the use of the basement will be for car parking, to help shoppers of the centre above (assignment two) for maximum shoppers. Location Streetscape: the streetscape of the building will be on Davidson Road, Hill Street and Amazon Highway, where the ground level will be two metres below Amazon Highway to remove some of the sound of the highway, whilst still advertising that there are shops there. Entrance: the location of the entrance will be on Davidson Road (shown in site plan). The reason for this is it is a more open location where an entrance would be. Exit: the location of the exit will be on Olive Street (shown in site plan). The reason for this is a quiet street for easy exiting to the road. Basement location: the basement will take up the whole area to allow for the highest amount of parking spaces; there will be a two metre inwards perimeter of the site, so that in the pathway can still be used. Clear site Clearing vegetation: 9 trees, 3 trees under 500mm, 6 trees 500/1000mm. Removal of trees: cost estimates, 500mm less $162 each, $162 each. Therefore total cost would accumulate to $1488. Volume (horizontal) Basement size: 2,900,000mm 2 Building floor area: 2,900,000mm 2 Volume (vertical) Depth: the depth of the basement will not go further than +56m from sea level (5 metres in depth) Amount of excavation: 14,911m 3 Cost of excavation: the cost of excavation of soft rock is $65.40m 3 Type of soil Reactive ability: there will be a combination of Made Ground : Very stiff (compacted) ashy sandy clay with brick and tile rubble and fine to coarse gravel, Medium dense becoming dense grey fine to coarse angular to sub rounded flint gravel with cobbles, and a trace of sand.

5 Compressive strength: the soils are closely dense, such that a foundation will need to be reinforced but will only have to be a shallow one. Water table Height: The water table does not go higher than +45m from sea level (16m in depth) and therefore there is no need to worry about the water level and the use of a water pump, yet still a need for waterproofing. Disposal Type: as there is no known location of the site or local disposal areas, this cannot be answered, but as shown in the mechanical disposal section (page) many different combinations can occur. It can be used as infill for another site. Distance: it is unknown.

6 Mechanical: Fixed: Name Picture Volume (V) Load (L)/ V x L / H Suited conditions Price hour (H) Shovel face farm4.static.flickr.com 0.3 6m m 3 Soil below or level and forwards N/A (was not in the Rawlinsons handbook 2010) Backhoe excavators101.com m m 3 Soil above dug down and backwards N/A (was not in the Rawlinsons handbook 2010) Clamshell, grab Dragline kensdiecastmodels.com m m 3 Soil deep below (even vertical) picked up N/A (was not in the Rawlinsons handbook 2010) 0.3-3m m 3 Coal Mines N/A (was not in the Rawlinsons handbook 2010) Summary: For the site and its contours as the basement will be dug from the east to the west the best fixed excavator would be the shovel face. Moving: Bulldozer Picture Depth Distance Action Price 400mm 100m Moving top soil and spreading the N/A (was not in the earth, flattening the land Rawlinsons handbook 2010) Loader classroomclipart.com 1000mm 200m Shallow excavation, slope excavation, loading material to transport system N/A (was not in the Rawlinsons handbook 2010) Scrapers coalcliff.com mm 3000m Collecting material, hauling it and discharging it, usually used in road. N/A (was not in the Rawlinsons handbook 2010) fhwa.dot.gov Summary: as the site is not very big the scraper is not useful, a combination of the loader and bulldozer would be the best was to move the material and load it onto the transport system.

7 Transport System: Transport Systems Dump trucks Conveyor Rail Picture Distance Suited Conditions Price elph.com.au motorsandbearingsconcept.com 0.8km 10km 1km 5km 5km 100km Close proximity removal, small to medium sized jobs Medium proximity removal, large sized jobs high longevity Far proximity removal, huge sized jobs, higher longevity N/A (was not in the Rawlinsons handbook 2010) N/A (was not in the Rawlinsons handbook 2010) N/A (was not in the Rawlinsons handbook 2010) northernrockiesrisingtide.files.wordpress.com/ Summary: as the location is unknown, there is no way to find out where the closest place is to relocate the soil, but just from the site plan the location is built up so the use of a conveyor belt is not the way to go. A combination of a dump truck and rail may need to be used if the relocating area is far away. But if close the use of only a dump truck would be a better option.

8 Excavation lateral support system: Method Picture Description Advantage Disadvantage Suitability Price Sheet pile: $54,750 permanent Sheet pile: Temporary Soldier pile Bored pile: continuous Bored pile: tangent Bored Pile: interlocking Bored pile: secant Diaphragm geelongadvertiser.com.au merelaconsultants.com sbe.napier.ac.uk Interlocking prefabricated steel piles that form a wall that is continuous and permanent Interlocking prefabricated steel piles that form a temporary wall Vertical steel H sections with horizontal timber lagging that sit in-between or behind Soldier piles that are repeated to create a wall Continuous bore piles that meet at their tangential axis Continuous bore piles that have in their gap secondary piles that are unreinforced weak concrete mix Continuous bore piles where the primary piles are the unreinforced piles and the secondary piles are reinforced A trench that is filled with slurry to prevent a collapse when reaching its depth reinforcement is lowered and the concrete displaces the slurry Light weight, adaptable, high resistance to tensile stresses Can be reused, adaptable Low cost, fast and easy to construct Stiff walls, good in confined site space, minimal vibration, low noise, flexible plan, avoids excessive excavation, can be used as footings Impermeable, can be used as the facade, flexible, little noise, deep work, lack of joints, can be used as footings Boulder obstruction, vibration, noise pollution, water seepage, cost, professional needed. Susceptible to the movement of ground. Slow, vertical joinery is difficult, low reinforcement Expensive, large area needed Harbour quays, restriction of water acting as a cofferdam Temporary restriction of water (cofferdam) to allow a basement, piers and houses that have a high water table Most suitable when the wall is above the water table, with free draining soils. Soldier piles are used mainly as they are cheap and don t disturb the surroundings as much as other walls Good for water tight needing areas, top down, used in very unstable soils $41,000 N/A (was not in the Rawlinsons handbook 2010) $8,200 $14,300 $21,000 $23,700 $69,000 Soil Nailing itm-ltd.com coastalcaisson.com Inserting near horizontal steel bars into ground and grouting over to stabilise the soil Cheap, light machinery, little noise, less rigid layout needed Soil loss, only for shallow depths Stabilize slopes or excavations. N/A (was not in the Rawlinsons handbook 2010)

9 Summary of Excavation lateral support systems: Permanent structural concrete wall formed in one operation ahead of excavation Substantially watertight wall preventing draw down to groundwater Ability to deal with obstructions economically Vertically better than 1:200 with little overbreak Lack of vibration/noise Temporary gaps left in wall to allow service diversions Vertical loads can be permanently carried Sheet pile: permanent x Sheet pile: temporary Soldier Bored pile: Bored pile: Bored Pile: Bored pile: Diaphragm pile contiguous tangent interlocking secant x x x x x x x x x x x x x x x x x x x x x x x x x x x Soil Nailing x x Summary: Due to the soil, the usefulness of how close it can get to the boundary and the use of it as a wall after excavation the diaphragm wall will be used. The diaphragm wall is also long lasting and therefore sustainable compared to the other methods that have to be replaced and fixed Ground Water Control: As the basement will not go deeper than 12.3 m there is no need to use any water pump during excavation. Summary: There is no need for ground water control during the excavation due to the depth of the building not exceeding the water table.

10 Foundation Construction method: Shallow foundation Method Picture Description Advantage Disadvantage Application price Pad A footing remote to broaden Hard soils, inert a load. soils Strip Raft 2.bp.blogspot.com lh5.ggpht.com moladi.com A footing that goes around the perimeter of the ground in a longitudinal direction where the load is. A single slab is poured with the reinforcement and footings all ready. Cheap, easy, simple, little materials used Strongest shallow foundation, can be changed for the different soils Lightweight, both slab and foundation created at once making it very strong Not good in weak soils. Or reactive soils Not good on highly reactive soils, more complicated than the pad footing Complicated compared to the pad footing, a lot of time in preparation has to take place Medium soils to hard soils Medium to hard soils Summary: Strip footings will be used as they are the strongest shallow footings, with the depth of the footings calculated by the engineer. As they are the strongest they will not need to be fixed or replaced and because of that it is quite sustainable. They will also be reinforced. N/A (was not in the Rawlinsons handbook 2010) (un reinforced) 248 cum (reinforced) 251cum 240 cum Deep footings Method Picture Description Advantage Disadvantage Application Piled (bedrock) The pile reaches Most solid Sometimes may Soft, reactive clays solid bedrock and foundation possible need to go very and soils can put all the deep to uncover weight on the bedrock bedrock. Piled (Friction) The pile does not reach any ground and has to use the friction around to allow the building to stand. Strongest foundation in locations without bedrock Complicated, many calculations need to be done and a lot of testing on the soil needed to ensure the footings will hold Soft, reactive clays and soils with no bedrock Caissons boredpiles.com Hollowed hole where concrete can be poured into More quiet than the other two deep footings. Time taken to make Soft, reactive clays and soils, where heavy machinery cannot be used kshitija.files.wordpress.com Summary: There is no need for deep footing as the soil below is quite stable.

11 Basement method: Method Open-cut Vertical cut Top-down Picture brhgarver.com simplex-foundations.co.uk personal.cityu.edu.hk/~bswmwong/pl.html Size of site Very large open site Small sized open site Large sized site Site environment Unobstructed Adaptable to most environments Adaptable to most complex environments Protection Simplest protection Complex lateral support required Limited shoring support where required Special provision Not much Not much Temporary vertical Soil removal Using ramp Staged platform or ramp Vertical shaft bucket or bucket Summary: Due to the use of the diaphragm wall, there are two choices, the vertical cut or the top down. The vertical cut is more suited for the site and will therefore be used as it is not a big site. Slab Type Picture Description Strength Price Concrete (in situ) 150mm thick, poured sqm concrete into a mould Precast Concrete underground.ie 150mm thick, concrete that is set off site and relocated to site. The strength can change with the additives used and the reinforcement used. For such a site no real additives need to be used as there are no large stresses upon the slab. But normal additives like super plasticizers to allow for higher workability concrete and pozzolans that increase the strength of the concrete will be used to help with strength and curing time sqm Summary: Both ways of creating a slab are strong, but because there are retaining walls that the slab has to fit into, in situ concrete will be used as it can chemically bond to the diaphragm wall making everything increasingly stronger.

12 Waterproofing Type Picture Description Advantage Disadvantage Price Liquid membrane A polymer liquid Good for complex Cannot be used 38m 2 that is painted on to structures under the slab form an impermeable barrier Bituminous paint img.alibaba.com A liquid that is painted on to form an impermeable barrier Good for complex structures Cannot be used under the slab 12.4m 2 Styrofoam A solid polymer that is solid and rigid that forms an impermeable barrier Can be used under the slab Not as useful as the other waterproof membranes in complex situations 22.4m 2 Polymer membrane A polymer that is solid but not rigid that forms an impermeable barrier Can be used for complex structures. Can be used under the slab. Time taken to set up can take some time. 28.2m 2 imghost1.indiamart.com Summary: As the slab is in situ the use of a polymer membrane or a Styrofoam membrane is the most useful as it can cover under the concrete. The polymer membrane will be used as it is better in difficult situations. It also doesn t have to be replaced unlike the bituminous paint so it will last a long time making it more sustainable.

13 Drainage Type Picture Description Advantage Disadvantage Price Tanking Creating an Water table can be Needs a pump, 12-38m 2 impermeable above the makes noise barrier that doesn t basement floor allow water in but if water does come in it gets pumped out Cavity drainage Exterior foundation drain oxfordbasements.co.uk Drainage that allows a gap in the membrane to a drainage channel. Drainage that uses an exterior system to drain away Un noticeable gaps Water table has to be below basement Has to have a flooring unit above the concrete, where the car park won t need it Most effective way of draining, that is quick Water table has to be below basement N/A (was not in the Rawlinsons handbook 2010) N/A (was not in the Rawlinsons handbook 2010) Summary: The use of the exterior foundation drain will be installed as the water table is 11m lower than the lowest point of the basement. The exterior foundation drain is also the quickest diffuse way of relocating water.

14 Columns Type Picture Description Strength Price Reinforced Concrete 200mm in diameter, with rebar Very strong sqm (in situ) reinforcement. Reinforced Precast Concrete 300X300 cast off site and delivered ready to lock into place Very strong sqm Steel 150X150 cast offsite, lightweight yet has no great compressive strength Medium sqm Timber Oregon wood 100X100. Not long lasting compared to the concrete Weak sqm Brickwork thepostandbeam.files.wordpress.com 350X230 although a strong column it takes a long time to make. Strong sqm img.archiexpo.com Summary: Concrete will be used as columns in this building being long lasting, as the timber and steel do corrode over time and the brickwork takes too long to make. The reason for in situ concrete is it can chemically join to the base plate making it a stronger bond

15 Suspended slab Type Picture Description Strength Price Concrete (in situ) 150mm thick, poured sqm concrete into a mould Precast Concrete underground.ie 150mm thick, concrete that is set off site and relocated to site. The strength can change with the additives used and the reinforcement used. For such a site no real additives need to be used as there are no large stresses upon the slab. But normal additives like super plasticizers to allow for higher workability concrete and pozzolans that increase the strength of the concrete will be used to help with strength and curing time. Summary: Precast concrete will be used as it will be easier to install and it is a lot easier for the precast concrete to be designed to create a waffle design making the slab lighter sqm

16 Cost Analysis: Area of cost Product Unit Price per unit Amount of products Price Cumulative price Earth moving: Tree >500mm Per tree $162 3 $496 $496 clearing the Tree Per tree $162 6 $992 $1488 site 1000>500mm Retaining wall Diaphragm wall Per m 2 $ m 2 $69000 $70488 Soil Excavation of soil Per m 2 $ ,911m 3 $975,179 $1,045,667 excavation for basement Footing Strip footings Per m 2 $ m 2 $141,360 $1,187,027 Waterproofing Polymer Per m 2 $28.2 2,900 m 2 $81,780 $1,268,807 membrane Drainage Exterior N/A N/A N/A N/A Foundation Drain Slab In situ Reinforced Per m 2 $161 2,900m 2 $466,900 $1,735,707 concrete Columns Reinforced in situ Per m 2 $201 2,900m 2 $609,000 $2,344,707 concrete Suspended Slab Precast reinforced waffle designed slab Per m 2 $120 2,900m 2 $348,000 $2,692,707

17 Pictorial Explanation: Process Description Perspective Plan 1. Analysis Entrance, exit, site size, orientation 2. Retaining wall Install guide wall, excavate trench, install rebar, check verticality, pour concrete 3. Excavation Vertically cutting the soil to open up the site

18 4. Set up Set up and install footings, install waterproof membrane, drainage installed and rebar 5. Ground Slab Pouring the slab onto set up 6. Columns Set up and pouring columns into place

19 7. Suspended Slab Crane suspended precast slabs onto the allocated points.

20 Conclusion: A diaphragm wall will be set up and the site will be open cut by shovel faces and backhoes then bulldozers will flatten it out. It is still unknown how or where the soil will be transported but will most likely be done by a dump truck. There is no need for ground water control due to the low water table and the footings will be strip due to their strength and ability to work around the site. The slab will be in situ concrete with additives like pozzolans and super plasticizers to increase strength and for higher workability. To waterproof the basement a polymer membrane will be below the slab, with the retaining wall also being impermeable. Yet if any water does come in exterior fountain drains will allow the water to go into the ground as the water table is quite low. In situ concrete columns will hold up the precast concrete slabs that are suspended and will be the base of the ground floor that is two metres below the highway to diffuse the sound.

21 Bibliography: Book: Rawlinson's handbook, Perth, W.A. 2010: House Publishing Frederick S. Merritt, Jonathan T. Ricketts Building design and handbook, USA, 1994: McGraw-Hill Professional Publi R.A. Johnson Water-resisting basement - A Guide: Safeguarding New And Existing Basements Against Water And Dampness, Great Brittan, 1995: Construction Industry Research and Information Association Barry, R. (2001) The Construction of Buildings (Vol 4), 5th Edition, Blackwell Scientific Publications. Internet: Lectures: Dr. Patrick Tang Lecture 1: Introduction to the course 9/3/10 Dr. Patrick Tang Lecture 2: Basement Construction 16/3/10 Dr. Patrick Tang Lecture 3: Foundation Construction 23/3/10 Dr. Patrick Tang Lecture 4: Specification and Cost Estimation 30/3/10 Dr. Patrick Tang Lecture 5: Concrete Technology 1 6/4/10