development of pressure penetrating pipe(ppp) pile for enhancement of bearing capacity

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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

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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. Contents. 1. Introduction. 2. Durability Performance Test. 3. Load Test Plans. - PowerPoint PPT Presentation

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Page 1: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

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

2013.04.17

Do, Eunsu

Seoul National University Geotechnical & Geoenvironmental Engineering Lab

Page 2: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

1. Introduction

Contents

2. Durability Performance Test

3. Load Test Plans

4. Summary & Further Study

Page 3: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Introduction

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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)

Page 4: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Grouting

Introduction

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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

Page 5: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Durability Performance Test Certification of Test

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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 Manufacturer5MN Compression

testerCCH-5000KNI SIMADZU/JAPAN

Static data logger YCAM-500A KYOWA/JAPAN

Page 6: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Durability Performance Test Test object installation

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Hydraulic Pump

500Ton Load Cell

Test Ob-ject

Data Logger

Page 7: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Durability Performance Test Test Results

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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

Page 8: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Durability Performance Test After test completion

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Page 9: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Load Test Plans Purpose of Load Test

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Load-settlement relationships Bearing capacity of pile Load transfer analysis

Test # of pile 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

Page 10: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Load Test Plans Plans of Load Test

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Page 11: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Load Test Plans Considering Factors – Strain gage

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Strain gageStrain gage

Concrete Concrete Concrete

Soil Soil SoilWelding

Plate(Aluminum)

Welding Weld-ingSpacer Connecting

linesConnecting lines

Connecting lines

Plan 1 Plan 2 Plan 3

Φ216.3-12t, L=1mPipe pile Φ216.3-12t, L=1m

Pipe pile Φ216.3-12t, L=1m

Pipe pile

Page 12: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Load Test Plans Considering Factors – Strain gage

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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 welding 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)

Page 13: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Load Test Plans Considering Factors – Load Cell

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Hydraulic Jack

Hydraulic Jack Hydraulic Jack(50.0t

f)(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 PileΦ216.3-12t Φ216.3-12tΦ216.3-12t

Page 14: Development of Pressure Penetrating Pipe(PPP) Pile for Enhancement of Bearing Capacity

Summary & Further study

The PPP pile method has many advantages compared to the existing con-struction method. However, there are disadvantages and not many construc-tion 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 comple-tion.

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

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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