Development of Pressure Penetrating Pipe(PPP) Pile

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29 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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Development of Pressure Penetrating Pipe(PPP) Pile
for Enhancement of Bearing Capacity


2013.04.17


Do,
Eunsu



Seoul
National University


Geotechnical
&
Geoenvironmental

Engineering Lab





1. Introduction

Contents


2. Durability Performance Test


3. Load Test Plans


4. Summary & Further Study

Introduction

3/14


Concepts of PPP Pile



Method using hydraulic jacking device to penetrate pipe piles by pressure



Able to check bearing capacity by pressure of hydraulic jacking device



High workability in narrow areas (0.6m x 0.6m x

2m)



Small and light penetrating equipment


(4 small hydraulic jack + guide steel bar + pressure plate)

Grouting

Introduction

4/14

Advantages



No vibration or noise



No need to clear near pile after construction



Compact jacking devices



Construction possible for limited areas



Checking of correct pile bearing capacity possible

Disadvantages



Not many construction cases



Difficulty in penetration when amber or boulders exist

Research Plans



Estimation of pile bearing capacity through load tests





Load transfer analysis, base & shaft resistances



Assessment of penetration availability according to soil conditions





Check the applied load through load cell

Vibration, Noise, Dust

Durability Performance Test


Certification of Test

5/14



Test object: Hydraulic jacking device(50Ton)



Test method


1) Method: operate jacking device so a load of over 500kN is induced


2) Target lifetime:

6,667 cycles


3) Velocity: within 30 seconds per cycle


4) Load drop under 500kN or oil leaking should not happen after target lifetime



Environment of Laboratory: 25
±
5

, 50
±
25%



Test equipments

Test equipments

Model

Manufacturer

5MN

Compression
tester

CCH
-
5000KNI

SIMADZU/JAPAN

Static data logger

YCAM
-
500A

KYOWA/JAPAN

Durability Performance Test


Test object installation

6/14

Hydraulic Pump

500Ton Load Cell

Test
Object

Data Logger

Durability Performance Test


Test Results

7/14

0

100

200

300

500

400

600

Load(
kN
)

Repeat Count

0

100

200

300

500

400

600

Load(
kN
)

Repeat Count

500kN

6,667Times

Test object

Hydraulic

Jack
(50Ton)

Repeat count

6,667(cycles)>>1,000

Results

-

No oil leaking

-

load of over 500kN

induced

Durability Performance Test


After test completion

8/14

Load Test Plans


Purpose of Load Test

9/14



Load
-
settlement relationships



Bearing capacity of pile



Load transfer analysis

Test

# of

p
ile

Times

Load test

1

8 times


Plans of Load Test



Weathered rock placed in
relatively shallow
depths(5~8m)



Test pile installation depth:
10~15m

Load Test Plans


Plans of Load Test

10/14

Load Test Plans


Considering Factors


Strain gage

11/14

Strain gage

Strain gage

Concrete

Concrete

Concrete

Soil

Soil

Soil

Welding

Plate(Aluminum)

Welding

Weldin
g

Spacer

Connecting lines

Connecting lines

Connecting lines

Plan 1

Plan 2

Plan 3

Φ216.3
-
12t, L=1m

Pipe pile

Φ216.3
-
12t, L=1m

Pipe pile

Φ216.3
-
12t, L=1m

Pipe pile

Load Test Plans


Considering Factors


Strain gage

12/14

Plan

1

Plan

2

Plan 3

Detailed

Plan

Price

of strain gauge

400,000 won

25,000 won

200,000

won

Processing cost of pile

25,000 won

40,000

won

20,000 won

Damage from w
elding

Little

Little

Heat

transfer by bolt

Advantages

&

Disadvantages

-

Minimize damage

-

High cost

-

Limited depth(30cm)

-

Many similar
cases

-

Able to cut and
process surface

-

Low

reliability of data

-

Minimize effect of
stiffness

-

High cost

-

Limited depth(30cm)

Load Test Plans


Considering Factors


Load Cell

13/14

Hydraulic
Jack

Hydraulic Jack

Hydraulic
Jack

(50.0tf)

(50.0tf)

(50.0tf)

Concrete

Concrete

Concrete

Soil

Soil

Soil

Pressure Plate

Pressure Plate

Pressure Plate

Install
Plate

Install
Plate

Pipe Pile

Plan 1

Plan 2

Plan 3

Pipe Pile

Pipe Pile

Φ216.3
-
12t

Φ216.3
-
12t

Φ216.3
-
12t

Summary & Further study



The PPP pile method has many advantages compared to the existing construction
method. However, there are disadvantages and not many construction cases.



According to a result of the durability performance test, When a load of 500kN in
the hydraulic jack was induced, there are no oil leaking after test completion.



Load test plans were made considering the economic feasibility of strain gage and
the installation of load cell. Analysis on load transfer and bearing capacity of piles
will be conducted after completion of load test.


Summary


Further study

14/14



Estimation of pile bearing capacity through load tests





Load transfer analysis, base & shaft resistances



Assessment of penetration availability according to soil conditions





Check the applied load through load cell