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4.2Bored Piles - Coggle Diagram

- - - - A hole is bored or drilled by means of a mechanically operated auger into which the pile is to be cast.
      - Usually steel lining tubes are vibrated in, as the soil is taken out, to maintain the sides of the drilling
      - As the pile is cast, the lining tubes are gradually withdrawn.
      - The borehole could be from 400 mm diameter to 3 m diameter and could be as deep as 60 m.
      - Bored Piles can be designed to carry loads as high as 3500t for each pile
    - - 1.Install casing
      - 2.Bore out earth inside casing
      - 3.Bore to required depth
      - 4.Install rebar cage
      - 6.Concrete the pile
      - 5.Extract casing
- - - - Vibration free and low noise
      - They are Cast in place
      - Environmentally friendly piling system is ideally suited to installation in unstable soil conditions and urban environments.
    - - 1.Drilling until required depth
      - 2.Once required depth reached, Auger withdrawal and simultaneous concrete injection all the way up to borehole mouth
      - 3.Rebar cage is then positioned
  - - - To provide structural support
      - To underpin your foundation
      - To transfer loads
      - To enhance mass stability
      - This pile option will help you underpin your foundation, minimize foundation settlement, and are ideal when installing in areas with difficult soil makeup
      - To stop structural settlement
      - To support new loads in congested areas
      - Resisting uplift/Dynamic loads
      - Excavation support in confined areas
    - - 1.Drilling of Borehole
      - 2.Measure depth of borehole
      - 3.Cleaning of boredhole after drilling
      - 4.Preparing rebars (cutting and joining)
      - 5.Steel coupling to extend rebars
      - 6.Lower steel cage
      - 7.Mixing grout before pumping into BH
      - 8.Removal of drill rods upon completion
      - 9.Grout cubes for quality control
    - - This pile option is one of the most practical and cost-effective solutions. It offers easy installation with its compact, lightweight nature, and is great for confined or remote areas like steep slopes, basements, overpasses, and even river pier foundations and wetlands. It also can be installed at various angles and is capable of resisting axial and lateral loads.
- - - - The test detects potentially dangerous defects such as major cracks, necking, soil inclusions or voids and, in some situations, can determine unknown lengths of piles that support existing buildings.
      - The PIT test is a non-destructive method to evaluate a pile foundation element in order to confirm its integrity.
    - - Necking
      - Bulging
      - Cracks/break
    - - Defects can be discovered at an early stage and remedial work undertaken.
      - Testing can be carried out on any accessible pile.
      - The method is quick and economical.
      - A large number of piles can be tested in a single day (up to 200 piles dependant upon pile head access and adequate pile head preparation).
    - - The test does not give any information about the bearing capacity of the pile or its behaviour under load.
      - Major defects are easily detected but minor deficiencies such as loss of cover to steel or small soil inclusions may not be discovered.
      - The presence of debris at the pile toe can not be detected.
      - Gradual changes in cross section may not be detected.
  - - - Test done to verify the structural and geotechnical soundness of pile and also to predict settlement in other piles
      - Usual procedure is to increase load put on pile in stages until proposed working load and a certain factor of safety is reached then unload and leave load off until rebound or rise substantially ceases
      - Tested in three cycles
        
        1st cycle: 1.5x Design load
        
        2nd cycle: 2.0x Design load
        
        3rd cycle:Tests pile to its ultimate working load defined as 2.5-3.0x Design load
    - - Kent-ledge System (Compression Test only)
        
        Consists of precast concrete blocks that are safely stacked to form the reaction weight
        
        Main and secondary steel girders are connected on the pile in such a way that load can be distributed evenly
        
        System should be firmly wedged or bolted together to prevent slippage between members
      - Reaction Frame System (for both tension and compression)
    - - Ultimate Load Test
        
        Test done for verification of design
        
        Conducted to 2.5-3.0 times the working load, or until failure of pile
        
        Equipped to determine skin friction and end bearing
      - Working Load Test
        
        Quality control to test for workmanship
        
        Tested to 1.5-2.0 of working load
        
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