LOAD TRANSFER FROM PILE TO SOIL - i-astm.com · PDF fileload transfer from pile to soil p ... for the design of working piles.(pilot pile) ... pile cap. kentledge system (dead load)

LOAD TRANSFER FROM PILE TO SOIL

P

SOFT SOIL LAYER Q = SKIN FRICTIONr

HARD SOIL LAYERQ END BEARINGQ = END BEARINGb

LOAD TRANSFER FROM PILE TO SOIL

P

SOFT SOIL LAYER Q = SKIN FRICTIONr

HARD SOIL LAYERQ END BEARINGQ = END BEARINGb

MECHANCAL  PROPERTIES TEST‐ LOAD TEST  ‐ STATIC  METHOD‐ DYNAMIC  METHOD

PHYSICAL PROPERTIES TESTINTEGRITY TEST(SEISMIC TEST)‐ INTEGRITY TEST(SEISMIC TEST)‐ SONIC CORING TEST

OBJECT OF PILE  LOAD  TEST

→ TO  ENSURE  THAT FAILURE  DOES  NOTOCCUR BEFORE THE DESIGN LOAD (WORKING PILE)OCCUR  BEFORE  THE  DESIGN  LOAD (WORKING  PILE)

→ TO  DETERMINE  THE  ULTIMATE  BEARING  CAPACITY  FOR THE DESIGN OF WORKING PILES.(PILOT PILE)

→ TO INDICATE STRUCTURAL SOUNDNESS OF THE PILE→ TO  INDICATE  STRUCTURAL  SOUNDNESS  OF  THE  PILE.

→ TO  DETERMINE  LOAD – SETTLEMENT  BEHAVIOUR  OFA PILE TO PREDICT GROUP SETTLEMENT ORA  PILE  TO  PREDICT  GROUP  SETTLEMENT  OR DIFFERENTIAL  SETTLEMENT  OF  OTHER  PILES.

STATIC LOAD TEST

COMPRESSION TEST PCO SS O S‐ BUILDING‐ BRIDGE‐ OTHER HEAVY STRUCTURE‐ OTHER  HEAVY  STRUCTURE

TENSION TEST P

‐ LIGHT  STRUCTUREi.e., FRAME  STRUCTURE

‐ TRANSMITTION  LINE  STATIONUNDER  WIND  LOAD        

HORIZONTAL  LOAD  TEST‐ FOR  STRUCTURE  WITH PWIND  LOAD‐ EARTH  QUAKE‐ FOR  STRUCTURE  WITH

P

DYNAMIC  LOAD

COMPRESSION  TEST  PROCEDURE

MAINTAINED  LOADING  TESTMAINTAINED  LOADING  TEST

PROCEDURE

INCREASE  THE  LOAD  IN  STAGES  UNTIL  THE  PROPOSED

WORKING LOAD IS REACHED AND THEN UNLOADWORKING  LOAD  IS  REACHED  AND  THEN  UNLOAD.

INCREMENT  OF  LOAD  AT  EACH  STAGES  WILL  BE PERMITTED  WHEN  RATE  OF  SETTLEMENT  IS  LESS  THAN  0.25 mm./hr.

APPLICATION

FOR  WORKING  PILE  TEST  TO  DETERMINE  PILE  LOAD  BEHAVIOUR  IN  THE  REGION  OF  WORKING  LOAD  WITH  FACTOR  OF  SAFETY .

TEST  NEED  NOT  REQUIRE  TO  DAMAGE  THE  PILE.

COMPRESSION  TEST  PROCEDURE

CONSTANT RATE OF PENETRATION TEST (CRP TEST)CONSTANT  RATE  OF  PENETRATION  TEST  (CRP  TEST)

PROCEDURE

LOAD WILL BE INCREASE BY MAINTAING RATE OF SETTLEMENT (CONSTANTLOAD  WILL  BE  INCREASE  BY  MAINTAING  RATE  OF  SETTLEMENT  (CONSTANT  SPEED)  ABOUT  THE  SAME  AS  UNDRAINED  TEST  IN  LABORATORY . (0.25‐1.25  MM./MIN.FOR  COHESIVE  SOIL  OR  0.75‐2.50  MM./MIN.  FOR  COHESIONLESS  SOIL.)

APPLICATION

TO  DETERMINE  ULTIMATE  LOAD  OF  THE  PILE.  PILE  CAN  BE  DAMAGED.

PILOT PILE IS RECOMMENDEDPILOT  PILE  IS  RECOMMENDED.

COMPRESSION TEST SYSTEMCOMPRESSION TEST SYSTEM

COMPRESSION  TEST  SYSTEM

USING  KENTLEDGE  SYSTEM  (DEAD  LOAD)LOAD LESS THAN 500 TONS‐ LOAD  LESS  THAN  500  TONS

‐ NO  ANCHORAGE  AVILABLE  OR  POSSIBLE  FOR       ARRANGEMENT

‐ USE  CONCRETE  BOX,  STEEL  OR  SAND  AS  DEAD  LOAD.,

TEST WEIGHTS

WEDGESDIAL GAGES TEST BEAMS

REFERENCE BEAM

CROSS BEAMS

CRIBBING

CONCRETE PILE CAP

KENTLEDGE SYSTEM (DEAD LOAD)KENTLEDGE SYSTEM (DEAD LOAD)

COMPRESSION TEST SYSTEMCOMPRESSION TEST SYSTEM

TEST BEAMS

STEEL PLATE

HYDRAULICJACK

TEST PLATEDIAL GAGES

REFERENCEBEAM

ANCHOR PILETEST PILE

ANCHORAGE SYSTEM

TEST RESULT PRESENTATIONTEST  RESULT  PRESENTATION

LOAD  V.S.  SETTLEMENT  PLOT

TIME  V.S. SETTLEMENT  PLOT

TIME  V.S.  LOAD  PLOT

LOAD – SETTLEMENT – TIME  RELATIONSHIPS  OF  0.8 m DIA. X 50 m  BORED PILEBORED  PILE  

LOAD- SETTLEMENT CURVELOAD , Tons

0 100 200 300 400 500 600 700 800 900 10000.0

TIME - SETTLEMENT CURVETIME , hrs

0 20 40 60 80 100 120

CYCLE 1

-5.0

CYCLE 1

CYCLE 2

EMEN

T , m

m

0.0

-5.0

-10.0

CYCLE 2

NT

, mm -10.0

CYCLE 3SETT

LE -15.0

-20.0

-25.0

CYCLE 3

SETT

LEM

EN

-10.0

TIME - LOAD CURVE

ons CYCLE 2

CYCLE 3800

700

600

500CYCLE 3

-20.0

21 99

LOA

D ,

To

CYCLE 1

400

300

200

100

0

-25.0

-21.99 0 20 40 60 80 100 120

TIME , hrs

INTERPRETATION AND CRITERIAOF PILE LOAD TEST

COMPRESSION TESTTENSION TESTLATERAL TEST

ULITIMATE LOAD OF PILE

LOAD AT WHICH SETTLEMENT REACH 10% OF PILE DIAMETER

ULITIMATE LOAD OF PILE

- LOAD AT WHICH SETTLEMENT REACH 10% OF PILE DIAMETER (BEARING PILE)

- LOAD AT WHICH PILE CAN NOT TAKE ANY MORE LOAD FRICTION PILE (FRICTION PILE)

L O A D

T

QUL O A D

E N

T QU

T L

E M

E N

T

S E

T T

L E

M

S E

T

FRICTION PILE

S

BEARING PILE10 % Ø

- IN GENERAL, STRUCTURAL BUILDING ARE NOT PREMITTED FOR SETTLEMENT GREATER THAN 25 MM. FOR SIMPLEFOR SETTLEMENT GREATER THAN 25 MM. FOR SIMPLE BEAM DESIGN

Compare Davisson and Chin Method

CHIN' S METHODSETTLEMENT / LOAD, mm/Ton00 50 100 150 200 250 300

P = 174 Tons

DAVISSON ' S METHOD LOAD, Tons

00 0.02 0.04 0.06 0.08 0.10 0.12

-5

0.14

-5CYCLE 2

P = 174 Tons.ult

-10

ENT

,mm

-10

T ,m

m

-15

-20 y = -205.21x + 2.0403 P = 205 Tons

SETT

LEM

Eult

-15

-20 Davisson' s Criteria3 81+8 331+2d+PL/AE i

CHIN' S

SETT

LEM

ENT

-25

30

-25 AssumptionsE = 631 t / cm²

= 3.81+8.331+2d+PL/AE, in mmwhere d is pile size in m.

-30

-30

ULTIMATE TENSION LOADULTIMATE TENSION LOAD

ULTIMATE LATERAL LOAD