Bored Pile Procedure

Content

Bored Pile Procedure : 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

Bored Pile Procedure

1. Set up the location of Bored Pile

Bored Pile Procedure

We use Total Station instrument to survey each pile point.

Bored Pile Procedure

2. Insert casing casing must be stand vertical ( by checking verticality of casing when insert casing )

Bored Pile Procedure

use Vibrodriver or Vibrohamer to insert casing

Bored Pile Procedure

3. Drilling Drilling Machine : weight : 130tons BG - 40 drilling depth :

49m diameter : 3m

weight : 96tons BG - 28 drilling depth :

39m diameter : 2.5m

weight : 91tons SD - 515 drilling depth :

36m diameter : 2.5m

BG - 40

BG - 28

SD - 515

Bored Pile Procedure

4. Removing slimewhen finish drilling , we use Mechanical pump equipment to remove slime .

Bored Pile Procedure

5. KODEN TestKODEN 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

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.

Bored Pile Procedure

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.

Bored Pile Procedure

6. Insert of steel cage

Bored Pile Procedure

7. Insert Tremie

Bored Pile Procedure

Type of tremie pipe :

we have 3 types of tremie : 1m, 2m and 3m Length

3m L

eng

th

1m L

eng

th

2m L

eng

th

Bored Pile Procedure

How to insert tremie pipe :

1. Use mobile crane to hang the hopper 2. Then connect each tremie pipe3. After that put it into the bored pile hole

until bottom

When we pour concrete, we have to burythe tremie pipe into concrete as below :

Diameter of Bored Pile

Buried Length of Tremie

Ø1000 3 to 3.5m

Ø1800 2 to 2.5m

Bored Pile Procedure

8. Pouring the concrete

Quality of Concrete : Max. size of Aggregate : 2.5cm Workability : 55cm ( Flow )

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 = 29.42 Mpa

Strength of mix

29.42 Mpa + 8.5 Mpa = 37.92 Mpa = 389 kg/cm²

Apply : 400 kg/cm²

Bored Pile Procedure

9. Remove casing

Cycle Time of a Bored Pile

Step of Bored PileCycle 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 1

6. Inserting Steel Cage 2

7. Inserting Tremie Pipe 1

8. Pouring the concrete 2

9. Remove casing 1.5

Total Cycle Time 18.8

Thank You for Your Attention!