2 Content Bored Pile Procedure : Cycle Time of a Bored Pile 1. Set up the Location of Bored Pile2. Insert Casing3. Drilling4. Removing Slime5. KODEN-Test6. Insert of Steel Cage7. Insert Tremie Pipe8. Pouring the Concrete9. Removing CasingCycle Time of a Bored Pile
3 Bored Pile Procedure1. Set up the location of Bored Pile
4 Bored Pile ProcedureWe use Total Station instrument to survey each pile point.
5 casing must be stand vertical Bored Pile Procedure2. Insert casing casing must be stand vertical( by checking verticality of casing when insert casing )
6 Bored Pile Procedure use Vibrodriver or Vibrohamer to insert casing
8 Bored Pile Procedure 4. Removing slime when finish drilling , we use Mechanical pump equipment to remove slime .
9 Bored Pile Procedure 5. KODEN Test KODEN test utilizes the principle of ultrasonic wave travel from sensor to the wall of drilled hole and reflect to the sensor through the bentonite slurry. EquipmentKODEN equipment consists of two parts, recorder unit and winch unit .Recorder UnitWinch Unit
10 Bored Pile ProcedureRecorder unit controls the operation and record the test result. On the other hand, winch unit lowers the probe (sensor) down the hole for ultrasonic reflection . Testing Procedure1. Remove any obstacle around the hole area in order that the test equipment can access to the hole .2. Place the winch unit over the top of drilled hole or on the steel casing. Position the sensor (probe) at the center of the hole .3. Lower the sensor into bentonite slurry. Hold the sensor at depth approximately 1 to 1.5m .4. Restore the sensor to the starting position and perform the test.
11 Bored Pile Procedure 1. Profile along two perpendicular axes. Test ResultTest results are presented in graphical plot and show characteristics below :1. Profile along two perpendicular axes.2. Average verticality of the hole.3. Location or depth where abnormalityOccurs such as reduction in diameter,or collapsed wall of the hole.4. Depth of drilled hole.
14 Bored Pile Procedure Type of tremie pipe : we have 3 types of tremie : 1m, 2m and 3m Length1m Length2m Length3m Length
15 Buried Length of Tremie Bored Pile ProcedureHow to insert tremie pipe :Use mobile crane to hang the hopperThen connect each tremie pipeAfter that put it into the bored pile holeuntil bottomWhen we pour concrete, we have to burythe tremie pipe into concrete as below :Diameter of Bored PileBuried Length of TremieØ10003 to 3.5mØ18002 to 2.5m
16 Bored Pile Procedure 8. Pouring the concrete Quality of Concrete : Max. size of Aggregate : 2.5cm Workability : 55cm ( Flow )
17 Strength of mix ( Target Strength ) Bored Pile Procedure Strength of concrete :► Design strength : fck =300kg/cm² ( 28day’s cure concrete )► Strength of mix ( Target Strength ) : according to the Standard Specifications of Concrete ( Korea Concrete Institute )Strength of mix ( Target Strength )So, for Actual Concrete Strength : 400kg/cm²MaterialStrengthCalculation offck ( Mpa )Strength of mix ( Mpa )Target Strength21 > fckfck + 7( Standard specifications of concrete )21 ≤ fck ≤ 35fck + 8.5( Korea Concrete Institute )fck > 35fck + 10fck300kg/cm² = MpaStrength of mix29.42 Mpa Mpa = Mpa = 389 kg/cm² Apply : 400 kg/cm²
19 Cycle Time of a Bored Pile Step of Bored PileCycle time of each step ( hour)1. Set up location of Bored Pile0.32. Inserting Casing23. Drilling84. Removing slime15. KODEN Test6. Inserting Steel Cage7. Inserting Tremie Pipe8. Pouring the concrete9. Remove casing1.5Total Cycle Time18.8