High Strain Pile Dynamic Analysis RAVIKIRAN - PART 3

ADVANCED NON DESTRUCTIVE TESTING PRACTICES

FOR PILE FOUNDATIONS

By: Ravikiran Vaidya Principal, Geo Dynamics (India)

HIGH STRAIN DYNAMIC PILE TESTING

DYNAMIC PILE TESTING EQUIPMENT

APPARATUS

• Compact Pile Driving Analyzer

• Sensitive Transducers• Signal Cables• Output Device

PRINCIPLE OF DYNAMIC PILE TESTING

STRAIN GAUGES

STRAINS

STRESS

FORCE

ACCELEROMETERS

ACCELERATION

VELOCITY

DISPLACEMENT

Rs = ( 1 – Jc )[ P1+ Z.v1 ]/2 + ( 1 + Jc )[ P2 – Z.v2 ]/2

Pile Resistance = Function (Force, Velocity)

Here,

Jc = soil damping

P1 & v1 = Force and Velocity at Time T1

P2 & v2 = Force and Velocity at Time T2

TEST SET-UP ARRANGEMENTS

PREPARATION FOR FIXING SENSORS

•Drilling holes diametrically on either side

Sensors fixed on the pile

USE OF TRIPOD/CRANE FOR TESTING

PDA TEST IN PROGRESS

TEST SET-UP ARRANGEMENTS

• HAMMER WEIGHT = 1% - 2% OF TEST LOAD

• BUILD PILE HEAD = 1.6 x PILE DIAMETER

• PLYWOOD CUSHION = 25mm - 50mm

• STEEL PLATE = 25mm - 50mm

• GUIDE TO ENSURE VERTICAL FALL (Optional)

• MINIMUM WAIT PERIOD = 7 – 10 DAYS

PDA INPUT PARAMETERS

•Pile Properties (at Sensor Location)• Area • Length below sensors and in soil

• Material Properties• Density SP•Wave Speed WS• Elastic Modulus EM• EM = c2 = (SP/g) WS2

• Damping Factor Jc = 0.5 to 0.9

PDA OUTPUT GRAPHSGEO DYNAMICS Pile Driving Analyzer ®

TP1

TS: 204.8

TB: 0.0

F1 (60000)

F2 (60000)

A12 F12

TS: 204.8

TB: 0.0

V1 (4.76)

V2 (4.76)

68 @ 66.5 m

Project InformationPROJECT: PILE NAME: TP1DESCR: 1300MMOPERATOR: GEO DYNAMICSFILE: TP1.w019/4/2010 6:35:31 PMBlow Number 4

Pile PropertiesLEAREMSPWSEA/C2L/CJCLP

mcm^2MPakN/m3m/skN-s/mms[]m

71.513273.23

3607624.5

3800.01260137.620.7070.3

Quantity ResultsCSXCSITSXEMXFMXDFNRMXRSUDMX

MPaMPaMPakN-mkNmmkNkNmm

16.019.73.8

146.321197

36780

1222910

SensorsF1: [6346] 97.6 (1)F2: [B474] 92.5 (1)A1: [24207] 1035 g's/v (1)A2: [24209] 1050 g's/v (1)CLIP: OKF1/F2: HIGH 1.60V1/V2: OK 1.10

Version 2008.098.031

PILE INFORMATION / RESULTS

GEO DYNAMICS Pile Driving Analyzer ®

TP1

TS: 204.8

TB: 0.0

F1 (60000)

F2 (60000)

A12 F12

TS: 204.8

TB: 0.0

V1 (4.76)

V2 (4.76)

68 @ 66.5 m

Project InformationPROJECT: PILE NAME: TP1DESCR: 1300MMOPERATOR: GEO DYNAMICSFILE: TP1.w019/4/2010 6:35:31 PMBlow Number 4

Pile PropertiesLEAREMSPWSEA/C2L/CJCLP

mcm^2MPakN/m3m/skN-s/mms[]m

71.513273.23

3607624.5

3800.01260137.620.7070.3

Quantity ResultsCSXCSITSXEMXFMXDFNRMXRSUDMX

MPaMPaMPakN-mkNmmkNkNmm

16.019.73.8

146.321197

36780

1222910

SensorsF1: [6346] 97.6 (1)F2: [B474] 92.5 (1)A1: [24207] 1035 g's/v (1)A2: [24209] 1050 g's/v (1)CLIP: OKF1/F2: HIGH 1.60V1/V2: OK 1.10

Version 2008.098.031

SOLUTION FOR SOIL PARAMETERSFrom Field Data, we obtain

F measured V measuredF = V x Z, Fm = Vm x Z

Here, Zp = Pile Impedance = EA/C, Rs = Soil Resistance

Consider, Fcomputed (Fc) = Vm x Zp

Hence Fm = Fc + (Vm x Rs)

• Only unknown is Rs, which is computed

• Discretize the pile into series of elements toobtain Rs at various distances from top

Fm = Vm x (Zp + Rs)= (Vm x Zp) + (Vm x Rs)

CAPWAP METHODCAPWAP METHOD

1 Set up pile model and assumesoil model for RRshaftshaft and RRtoetoe

RRshaftshaft

RRtoetoe

5 Go to step 2

4 Adjust RRshaftshaft and RRtoetoe

3 Compare FFcc with measured FFmm

2 Apply one measured curve ((vvmm));Calculate complementary FFcc

vvmmFFcc

FFmm

Repeat until match Repeat until match is satisfactoryis satisfactory

20 100

-15000

0

15000

30000

ms

kN

4 L/c

Force MsdForce Cpt

20 100

-15000

0

15000

30000

ms

kN

4 L/c

Force MsdVelocity Msd

Pile

0

200

400

600

800

kN

/m

0

3750

7500

11250

15000

kN

Shaf t ResistanceDistribution

Pile Forceat Ru

0 3750 7500 11250 150000.000

5.000

10.000

15.000

20.000

Load (kN)

Dis

pla

ce

me

nt

(mm

)

Pile TopBottom

Ru = 12624.5 kNRs = 10752.1 kNRb = 1872.4 kNDy = 15.0 mmDx = 17.0 mm

Pile: TP1; 1300MM; Blow: 2 (Test: 04-Sep-2010 18:35:) 23-Oct-2010GEO DYNAMICS CAPWAP(R) 2006-2

CAPWAP(R) 2006-2 Licensed to GEO DYNAMICS

SAMPLE OUTPUT OF CAPWAP

OUTPUT QUANTITIES OF CAPWAP

• Static Capacity At Time Of Testing.

• Static Load Test Curve.

• Total Skin Friction And End Bearing.

• Skin Friction Variation Along The Pile Length.

• Compressive And Tensile Stresses Developed During Testing.

• Net And Total Displacement Of The Pile.

• Pile Integrity And Changes In Cross-Section.

RELIABILITY STUDIES END-BEARING PILES

KURLA FLYOVER , MUMBAIPILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1200mm

Pile Depth 20.80m

Design Load 339.3Tons

Test Load 509.0Tons

Soil Type Weathered Rock

PDA Test 28.09.98

Static Test 12.09.98

0 100 200

300 400 500 600

Load in Tons

0.0

1.0

2.0

3.0

Pile

top

settl

emen

t in

mm --Static Load Test Curve

--Dynamic Load Test Curve

JJ URBAN VIADUCT , MUMBAI

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1200 mm

Pile Depth 7.0 m

Design Load 550.0 T

Test Load 1375.0 T

Soil Type Fresh Basalt

PDA test 21.05.99


0 200 400 600 800 1000 1200 1400 1600

Load in Tons

0.0

1.0

2.0

3.0

4.0

5.0

Pile

top

settl

emen

t in

mm --Static Load Test Curve


BORIVALI NATIONAL PARK FLYOVER, MUMBAI

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1000 mm

Pile Depth 8.6 m

Design Load 235 T

Test Load 352.5 T

Soil Type Fresh Basalt

PDA test 23.05.99


0 100 200 300 400 500

Load in Tons

0.0

0.5

1.0

1.5

2.0

Pile

top

settl

emen

t in

mm

--Static Load Test Curve


0

2

4

6

8

10

12

14

16

0 200 400 600

800 1000 1200

Load in tons

Pile

Top

Set

tlem

ent i

n m

m

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1200 mm

Pile Depth 18.0 m

Design Load 675 T

Test Load 1012.5 T

Soil Type Indeterminate Weathered Rock

PDA test 24.01.08

Static Test 06.11.07-07.11.07

ELEVATED HIGHWAY PROJECT, BANGALORE

RELIABILITY STUDIESFOR FRICTION PILES

AHMEDABAD-VADODARA EXPRESSWAYPHASE -II

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 500mm

Pile Depth 20.50m


Test Load 105.0Tons

Soil Type Silty Clay

Dynamic test 16.01.02


0

1

2

3

4

5

6

0 20 40 60 80 100 120 140 160 180Load in tons

Pile

Top

Set

tlem

ent

in m

m



CHENNAI BYPASS PROJECT

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1200mm

Pile Depth 23.70m


Test Load 875.0Tons

Soil Type Dense Silty Sand

PDA test 17.09.05


0

2

4

6

8

10

0 100 200 300 400 500 600 700 800 900 1000

Load in tons

Pile

Top

Set

tlem

ent i

n m

m



GCPTCL JETTY, DAHEJ

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1200mm

Pile Depth 34.70m


Test Load 412.8Tons

Soil Type Dense Sand

PDA Test 17.09.05


0

1

2

3

4

5

0 100 200 300 400 500

Load in tons

Pile

Top

Set

tlem

ent i

n m

m



HEBBAL GRADE SEPARATOR, BLR

0

2

4

6

8

10

0 100 200 300 400 500 600

L o a d i n t o n s

P i l

e T

o p

S e

t t l

e m

e n

t i

n m

m

PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1200mm

Pile Depth 34.70m


Test Load 412.8Tons

Soil Type Murum & W.D. Rock

PDA test 17.09.05




DMRC PROJECT, NEW DELHI

Delhi Metro Rail Corporation Project, New Delhi

0

2

4

6

8

0 100 200 300 400 500 600 700 800L o a d i n t o n s

mm

--Static load test curve--Dynamic load test curve

0

2

4

6

8

0 100 200 300 400 500 600 700 800

L o a d i n t o n s

P I l

e T

o p

S e

t t l

e m

e n

t i

nm

m

PILE DETAILS

Type of Pile R.C.Bored

Dia of the pile 1500mm

Pile Depth 37.15m


Test Load 434.6Tons

Soil Type

Dynamic test 20.03.02



--Dynamic Load Test Curve0

5

10

15

20

25

30

0 100 200 300 400 500 600 700 800 900

L o a d i n t o n s

P i l

e T

o p

S e

t t l

e m

e n

t i

n m

m



PILE DETAILS

Pile Type R.C.Bored

Pile Dia. 1000mm

Pile Depth 43.5m

Design Load 360.0 Tons

Test Load 520.0 Tons

Soil Type

PDA test 11.05.07

Static Test 18.028.07-19.02.2007

PEEVEES COCHIN MALL PROJECT

0

1

2

3

4

5

6

7

8

9

10

0 100 200 300 400 500 600 700Load in tons

Pile

Top

Set

tlem

ent i

n m

m

Static Load Test CurveDynamic Load Test Curve

BENEFITS & APPLICATIONS

• Both PDA / PIT Have Proven Application Worldwide

• Applicable both Offshore & Onshore for Bored, Driven Concrete, Steel, Timber Piles

• Generates Useful Information other than pile capacity

• More tests can be conducted & hence Better Quality Assurance

• Tests conducted by Independent Agency

• Requires Less space compared to Static Tests

• More Safety Compared to Static Testing

• Evaluates Pile Integrity Incl. Extent & Location of Damage

• Determines if Problem is Pile, Soil or Hammer

• Confirms Capacity, Even at Large Loads

• Expertise essential for interpretation and data collection CAPWAP mandatory for all bored piles and atleast first few initial driven piles

• Reliability studies important to assess knowledge of testing company and in some cases to calibrate with soil.

• Method can be used for almost all pile types

• Technology is a part of IRC and various code provisions.

• Recommended on 2%-10% of total piles at the project site

CONCLUSIONS

Documents

High Strain Pile Dynamic Analysis RAVIKIRAN - PART 3