LOAD CAPACITY OF PILE FROM DRIVING FORMULA

ByM. Firdaus, MTwww.dauspoli.co.cchttp://dauspoli.host56.com

Basic Calculation :Incoming energy = Energy used + missing energy

Use formula of Chellis (general formula) :

Ce

H.MQu

E = Qu.e + ΔE

E = Qu.e + Qu.C ,where : C = missing energy constantaM. H = Qu.(e + C)

'

'2

321

'

MM

M.rM.f.

eee21

e

H.M.

FS

1

Dengan : P’ = Allowable capacity of pile (kN)Dengan : P’ = Allowable capacity of pile (kN) F = safety factorF = safety factor M = hammer weight (kN)M = hammer weight (kN) MM’ ’ = pile weight(kN)= pile weight(kN) H = High fall to pilehead (m)H = High fall to pilehead (m) e = entry of the pile as a blow (per 1 times) (m)e = entry of the pile as a blow (per 1 times) (m) f = hammer efficiency(0,75-1)f = hammer efficiency(0,75-1) r = coefficient of resilience pile(=0,25)r = coefficient of resilience pile(=0,25) ee11= loss of power due to elasticity pole= loss of power due to elasticity pole ee22= loss of power at the pilehead= loss of power at the pilehead ee33= loss of power at the pile tip to the ground= loss of power at the pile tip to the ground

Engineering News Formula Modification:

'

'2'

MM

M.(0,25)M.f.

0,25e

H.M

6

1Ρ

Calendering of Pile

• In determining the carrying capacity of a permit erection of piles in the field

• To monitor the reduction in pile field directly.

Calendering phase of the pile :

1. In the pulverization end with a reduced pile was not visible, graph paper mounted on pile

2. A horizontal line was made on millimeter paper refers to the area under the signboard

3. Pile was hit several times with a certain number of strokes (eg. 1,2,5, or 10) then the stake will come down again

4. Created a line after a certain number of blows5. Distance lines that have been made in measuring. If the distance is not

yet qualified, repeat again to pulverization proccess, making the line, and distance measurement

6. If the decline is compliant, then archived.

Calendering of pile driving procedure:

23 cm

Layout :

Back to Exam

Example Problem

A building construction will use a concrete pile foundation 04 x 0,4 m and a length of 20 m. Penetration of the end of the data according to calendering, with a single action hammer weight of 30 kN with a high fall 1.5 m. With 24 kN/m3 of volume weight of concrete, calculate of allouwable bearing capacity?

From the example problems :

'

'2'

MM

M.(0,25)M.f.

0,25e

H.M

6

1Ρ

e = 2,3 cm = 0,023 m

A pile = 0,4 x 0,4 = 0,16 m2

L pile = 20 mγ pile = 24 kN/m3

M = 30 kNH = 1,5 m

Question : P’ = ?

Conclution :M’ = A pile x L pile x γ pile = 0,16 x 20 x 24

take f = 1Enter to formula hilley :

'

'2'

,

,.(0,25)..

0,25,

,.

6

1Ρ

87630

876301

0230

5130

So, P’=

= 76,8 kN

8,952 kN

Exam :A building construction will use a concrete pile foundation (4Ax4A) cm and a length 2B m. Penetration of the end of the data according to calendering, with hammer weight single action 1AB kN with a high weight fall 1.5 m. 24 kN/m3 volume weight of concrete, calculate of allowable bearing capacity for single pile?