J.S. Daniel paper for roads and bridges construction methods & resources


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J.S. Daniel paper for roads and bridges construction methods & resources

  1. 1. Roads and BridgesConstruction Methods & resources by: 1 Jihad Daniel
  2. 2. Types of Roads• Various types of roads are in use around the world. Roads range in size from private driveways, to the stereotypical two-lane highways, to high capacity dual carriageway routes, such as freeways and motorways. • In addition, depending on their types, roads may have different types of junction. 2
  3. 3. Types of Junctions Bridge interchange Intersection Flyover and underpasses Junctions at grade Interchange at grade 3
  4. 4. Types of Junctions• Interchange at grade • Intersection at grade 4
  5. 5. Types of Junctions• Flyovers • Bridge interchange 5
  6. 6. Road Structure• Cross section of a road: main road situated outside towns and cities.• Platform: horizontal surface raised above the surrounding ground.• Shoulder: space between the roadway and the ditch.• Median strip: separation between two carriageway.• Wearing course: surface layer of the road (asphalt).• Carriageway: central part reserved for vehicle traffic.• Ditch: channel that carries away water. 6
  7. 7. Road Structure• Subgrade: upper surface of platform. (this is valid in a cut section)• In a Fill Section, the embankment constitute the platform and the subgrade.• Subbase: lower surface of a road structure.• Base course: main foundation element (bituminous / granular).• Wearing Course (Bituminous in general) 7
  8. 8. Road Profile• The right of way ground formation maybe, as the road profile requires, natural ground, cut or fill. In case of fill, ground formation is filled in layers to comply with the profile. The work is called embankment.• Embankment is made in layers with thickness varying from 20 to 40 cm depending on the material used.• In case of cut this could be open cut or tunnel. 8
  9. 9. MaterialsSelected Crushed Asphaltic Roads fill aggregate concrete 9
  10. 10. Road Furniture and Incidental WorksRoad furniture refers toall fixtures in the roadreserve. The termincludes fixtures on theroad surface such as:- Signs,- Markings,- Safety barriers,- Road studs, etc. 10
  11. 11. Method of ConstructionThe system is based on a monthly output ofmajor work items using the minimumequipment considered necessary to carry out thework during a month of 25 working days, eachday being 8 working hours. 11
  12. 12. Road works planning criteria• Planning road works, as a first step, depends on the extent of earthmoving quantities.• Generally, the most driving is the fill making the embankment, especially for the case of high embankments.• The basic equipment is as follows: 12
  13. 13. FillFrom Common Excavation of Borrow Excavation: Basic Equipment for One Work TeamNo. of Items Item 6 Dump Trucks (8 m3), 12 to 15 Tons 1 Front-end Loader (2m3 bucket) 1 Motor Grader (150 hp) 2 Water Trucks (12 m3) 1 Vibratory Roller (40 kw) 1 Farm Tractor (if roller is not self- propelled) 13
  14. 14. Cut & FillFrom Common Excavation or Borrow Excavation: Basic Equipment for Two Work TeamsNo. of Items Item 12 Dump Trucks (8 m3) 2 Front-end Loader (2 m3) 2 Bulldozers (200-300 hp) 3 Motor Grader (150 hp) 2 Vibratory Rollers (40 kw) 6 Water Tanker Trucks (12,000 liters) 2 Farm Tractors (if roller is not self- propelled) 1 Pneumatic Roller (25 mg) 14
  15. 15. Production ratesAssuming:Number of dump trucks =12Truck capacity = 8 m3 per truckAverage haul distance=1 km (from borrow pit/stockpile to job site)Number of cycles : (Cycle time 8 minutes)Efficiency on truck capacity: 70%Therefore, rate (2 teams) of 100,000 m3/month based on the following use a basic production: Production Rate = 12 x 8 x 60/8 x 0.7 x 25 x 8 = 100,800 m3/month • For quantities up to 1,500,000 m3 use the basic production rate of 100,000 m3/month (2 work teams) • For quantities between 1,500,000 m3 and 2,500,000 m3 adjust the equipment to provide a production rate of 150,000 m3/month (3 work teams) 15
  16. 16. Production rates (cont’d) • For quantities greater than 2,500,000 m3 adjust the equipment to provide a minimum production rate of 200,000 m3/month (4 work teams). • The overall monthly production rate shall be adjusted to allow 2 months buildup prior to peak production and 1 month slow down prior to completion of the work. The quantity of embankment placed should be converted in road length terms to enable the planner to define the interface between subsequent activities. (e.g. when to start sub-base activities after embankment) 16
  17. 17. Production rates (cont’d) Planning the amount of earthworks and defining the time required to place the whole quantity would be as follows: 1st month 50,000 m3 2nd month 100,000 m3 3rd (last month) 50,000 m3• Duration = 1500,000 – (50,000 + 100,000 + 50,000) 100,000 = 13 months Using higher capacity trucks and improving efficiency would reduce this duration. 17
  18. 18. Bulldozer 18
  19. 19. grader 19
  20. 20. ASPHALT PAVEMENT Basic Equipment for Two Work Teams No. of Items Item 2 Paver 6-12 Dump Truck (35 tons) (number depends on hauled distance) 2 Bulldozers (200-300 hp) 1 Steel Roller 2 Rubber Rollers 1 Water Tanker Truck 1 Prime/Tack Coat Spreader 6-8 Laborers 20
  21. 21. ASPHALT PAVEMENT Production Rates Equipment Production RatePrime Coat Spreader 2 km of road, full widthTack Coat Spreader 3 km of road, full widthAsphalt Placing Crew 2,500 tons (1,000 m3) per day – 6 no. 35 tons trucks with hauling distance up to 10 km Dump Truck Cycle Depends on number of trucks, truck capacity, efficiency factor, cycle time Production Rate Usually report on daily or weekly basis 21
  24. 24. Finished Road 24
  25. 25. Finished Road 25
  26. 26. Railways• There are many similarities between railways and roads, in the way of construction and material used, till top of embankment level (sub- grade for roads and sub- ballast for railways)• Above this level, the activities are completely different starting with ballast and sleepers laying. 26
  27. 27. Bridges• Bridges can be of different nature and types. They can be made of steel, concrete and other materials such as stones, timber, etc.• They can be skew, straight, curved, flat or arched. The presentation will be limited to straight concrete structured bridges.• The spans vary between long, medium and short spans. Long 50- 350 or more meters Medium 30-45 meters Short 12-25 meters 27
  28. 28. BridgesThe deck structure andmethod of constructionare dependent on thespan length, pier heightand accessibility. • Long span bridges are cable stayed. • Medium span bridges are box girder type. 28
  29. 29. Bridge deck types • Example of box girder• Example of girder and slab 29
  30. 30. Method of ConstructionThe substructure: • Footings on solid ground or piles • Piers with or without a cross headThe superstructure of deck: • Girder and slab • Box girderDeck and piers are often in contact via elastomericbearings.Parapets are complementary to the deck. They areinstalled/cast subsequent to deck casting 30
  31. 31. Cast-in-situbox girder deck 31
  32. 32. Fragnet for typicalbridge construction 32
  33. 33. Fragnet for typicalbridge construction 33