1. Bored Pile Procedure

2. Content Bored Pile Procedure : Cycle Time of a Bored Pile
1. Set up the Location of Bored Pile
2. Insert Casing
3. Drilling
4. Removing Slime
5. KODEN-Test
6. Insert of Steel Cage
7. Insert Tremie Pipe
8. Pouring the Concrete
9. Removing Casing
Cycle Time of a Bored Pile

3. Bored Pile Procedure
1. Set up the location of Bored Pile

4. Bored Pile Procedure
We use Total Station instrument to survey each pile point.

5.  casing must be stand vertical
Bored Pile Procedure
2. 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

7. Bored Pile Procedure 3. Drilling  Drilling Machine : weight : 130tons
BG drilling depth : 49m
diameter : 3m
weight : 96tons
BG drilling depth : 39m
diameter : 2.5m
weight : 91tons
SD drilling depth : 36m
BG - 40
BG - 28
SD - 515

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.
 Equipment
KODEN equipment consists of two parts, recorder unit and winch unit .
Recorder Unit
Winch Unit

10. Bored Pile Procedure
Recorder 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 Procedure
1. 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 Result
Test 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 abnormality
Occurs such as reduction in diameter,
or collapsed wall of the hole.
4. Depth of drilled hole.

12. Bored Pile Procedure
6. Insert of steel cage

13. Bored Pile Procedure
7. Insert Tremie

14. Bored Pile Procedure Type of tremie pipe :
we have 3 types of tremie : 1m, 2m and 3m Length
1m Length
2m Length
3m Length

15. Buried Length of Tremie
Bored Pile Procedure
How to insert tremie pipe :
Use mobile crane to hang the hopper
Then connect each tremie pipe
After that put it into the bored pile hole
until bottom
When we pour concrete, we have to bury
the tremie pipe into concrete as below :
Diameter of Bored Pile
Buried Length of Tremie
Ø1000
3 to 3.5m
Ø1800
2 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/cm²
Material
Strength
Calculation of
fck ( Mpa )
Strength of mix ( Mpa )
Target Strength
21 > fck
fck + 7
( Standard specifications of concrete )
21 ≤ fck ≤ 35
fck + 8.5
( Korea Concrete Institute )
fck > 35
fck + 10
fck
300kg/cm² = Mpa
Strength of mix
29.42 Mpa Mpa = Mpa = 389 kg/cm² Apply : 400 kg/cm²

18. Bored Pile Procedure
9. Remove casing

19. Cycle Time of a Bored Pile
Step of Bored Pile
Cycle time of each step ( hour)
1. Set up location of Bored Pile
0.3
2. Inserting Casing 2
3. Drilling 8
4. Removing slime 1
5. KODEN Test
6. Inserting Steel Cage
7. Inserting Tremie Pipe
8. Pouring the concrete
9. Remove casing
1.5
Total Cycle Time
18.8

20. Thank You for Your Attention!