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03/03/2012
1
DAYA DUKUNG FONDASI DALAM
TIANG PANCANG DAN TIANG BOR
Idrus Ir M.Sc IPM
PERHITUNGAN
PONDASI
Daya Dukung Aksial Pile
Daya Dukung Lateral PileAnalisis Group Pile
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Load Transfer Friksi
Load Transfer End Bearing
displacement
Friksi
0.4% Diameter Pile
displacement
EndBearing
6% Diameter Pile
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AXIAL LOAD TEST PILE #14
Lo
ad
(T
on
s)
Settlement (mm)
Friction(Elastic Zone)
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Settlement (mm)
AXIAL LOAD TEST FOR PILE #22L=45m, f=60 cm
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Rumus umum daya dukung aksial fondasi dalam:
Qult = Qs + Qp
Qs = Tahanan Geser Selimut TiangQp = Tahanan Ujung Tiang
DAYA DUKUNG AKSIAL
Qu = Qp + Qs
Qp
Qs =Σ2πr ∆l (α C)
+ Σ2πr ∆l (k σv tanδ)
.S.F
QQ u
all =
=Ap(c Nc +q Nq)
∆l
σv
κ σv
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Jenis HammerCara uji SPT
C (t/m2) = 2/3 N
N-SPT = Jumlah pukulan untuk memasukkan split spoon sedalam 30 cm
SPT (Standard Penetration Test)
Relationship between Cohesion and N-Value (Cohesive soil)
2/3 N
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Relationship between Angle of Internal Friction and N-Value (Sandy Soil)
Faktor Koreksi N – SPT Lapangan seusai dengan
Metoda Pelaksanaan Test:
Country
Hammer Type
Hammer Release
Estimated Rod Energy (%)
Correction Factor for 60% Rod Energy
Donut
Free Fall
78
78/60 = 1.30 Japan
Donut
Rope an Pulley with special throw release
67
67/60 = 1.12
Safety
Rope and Pulley
60
60/60 = 1.00 US
A
Donut
Rope and Pulley
45
45/60 = 0.75 Argentina
Donut
Rope and Pulley
45
45/60 = 0.75
Safety
Rope and Pulley
60
60/60 = 1.00 US
A
Donut
Rope and Pulley
45
45/60 = 0.75 Argentina
Donut
Rope and Pulley
45
45/60 = 0.75
Donut
Free Fall
60
60/60 = 1.00 China Donut
Rope and Pulley
50
50/60 = 0.83
Harga N free fall tidak perlu dikoreksi krn menjadi standard
Harga N rope and pulley harus dikalikan dengan 0.70
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CPT (Cone Penetration Test) atau Sondir CPT (Cone Penetration Test) atau Sondir
C= qc/(15 sampai 20) dalam kg/cm2
Tahanan Geser Selimut
Tanah Kohesif Tiang PancangTiang Bor
Tanah PasirTiang PancangTiang Bor
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Tahanan Geser Selimut Tiang :
1. Tahanan geser selimut tiang yang merupakan kontribusi dari Cohesi Tanah adalah:
Qs = αααα . Cu. Li. PDimana,αααα = Koefisien adhesi antara tanah dan tiangCu = Undrained CohesionLi = Panjang lapisan tanahp = keliling tiang
Tahanan Geser Selimut Tiang :
2. Tahanan geser selimut tiang yang merupakan kontribusi dari sudut geser dalam ( φφφφ) adalah:
Qs = fi.Li.pDimana,fi = tahanan geser selimut tiang per satuan luasfi = Ko . σσσσo’. Tan (2/3 . φφφφ)Li = Panjang lapisan tanahp = keliling tiang
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Faktor Adhesi (α) pada Tanah Kohesif untuk
“Tiang Pancang” :
1. API Metode - 2, 1986
Faktor Adhesi (α) pada Tanah Kohesif untuk
“Tiang Pancang” :
2. Tomlinson, 1977 :Tergantung pada
kondisi tanah.
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Faktor Adhesi (α) pada Tanah Kohesif untuk
“Tiang Bor” :
1. Reese and Wright, 1977 :Manurut Reese dan Wright koefisien αααα untuk bored pile adalah 0.55
2. Kulhawy, 1984( k N / m )
U n d r a in e d S h e a r in g R e s is t a n c e , s ( t s f )
Ad
hesio
n f
acto
r (
)
α
T o m l in s o n , 1 9 5 7 ( c o n c r e t e p ile s )
6 5 U 8 4 1 C lo a d t e s t s
= 0 . 2 1 + 0 .2 6 p / s ( < 1 )
u
α a u
S h a f t s in c o m p r e s s io n
S h a f t s in u p l i f t
2
D a t a g r o u p 1
D a t a g r o u p 2
D a t a g r o u p 3
D a t a g r o u p 3
D a t a g r o u p 2
D a t a g r o u p 1
Perbandingan Harga Faktor Adhesi (α) dari
Beberapa Metede pada Tanah Kohesif untuk
“Tiang Bor” :
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0 50 100 150 200 250 300
S u (kN/m 2)
ad
he
sio
n f
ac
tor
Design =( Kulhawy + Reese)/2
Kulhawy
ReeseC ore Team
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Faktor Adhesi (α) pada Tanah Kohesif untuk
“Tiang Bor” :
3. Reese and O’Neil, 1988 :
Undrained Shear Strength, Su
Value of α
< 2 tsf 2 – 3 tsf 3 – 4 tsf 4 – 5 tsf 5 – 6 tsf 6 – 7 tsf 7 – 8 tsf 8 – 9 tsf > 9 tsf
0.55 0.49 0.42 0.38 0.35 0.33 0.32 0.31
Treat as Rock
Tahanan Geser Selimut Tiang dari Tanah Berpasir
Menurut Naval Engineering Facilities Command:
1. Tiang Pancang :
Qs = 0.2 x (N SPT) x Li x p (ton)
2. Tiang Bor :
Qs = 0.1 x (N SPT) x Li x p (ton)
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Tahanan Geser Selimut Tiang Bor pada Tanah
Berpasir �Rojiani, Duncan and Barker (1991)
= 0.11 N (t/m2)
= 0.28 N (t/m2)
(=27.5 t/m2)
=0.32 N (t/m2) N < 53
Z=depth below ground surface
0.20 N
Tahanan Ujung
Tanah C dan φ untuk dasar teori
Tanah LempungTiang PancangTiang Bor
Tanah PasirTiang PancangTiang Bor
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Tahanan Unjung Tiang
- φ dan Cu
Tahanan Ujung Tiang Pada Umunya dinyatakan sebagai
persamaan :
Qp = Ap (c Nc* + q’ Nq*)
Dimana,
Qp = Tahanan Ujung Ultimate
Ap = Luas Penampang Tiang
C = Undrained kohesi
q = Over Bourden Pressure
Nc, Nq= Faktor daya dukung.
Beberapa Motode Penentuan Faktor Daya Dukung
- φ dan Cu
1. Meyerhoff, 1976
0 10 20 30 40 45
2
1
4
6
810
20
40
60
80100
200
400
600
800
1000
an
d
Soil friction angle, Ø (deg)
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Beberapa Motode Penentuan Faktor Daya Dukung:
2. Vesic, 1977Nc = (Nq – 1) cot φφφφ
Dimana, Nq = f(Irr)Nq* = 4/3 ln (Irr + 1) + ππππ/2 +1
I rr = I r Nilai I r ditunjukkan pada tabel dibawah:
Soil type Ir Sand 70 – 150 Silts and clays (drained condition) 50 – 100 Clays (undrained condition) 100 – 200
- φφφφ dan Cu
Beberapa Motode Penentuan Faktor Daya Dukung:
3. Janbu, 1976
S oil fr ictio n ang le , Ø (deg)
0 10 20 30 40 4 51
2
4
6
8
10
20
40
60
80
1 00
2 00
4 00
6 00
8 0010 00
an
d
- φφφφ dan Cu
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Daya Dukung Ujung untuk Tanah Kohesif Cu
Tiang Pancang dan Tiang Bor:
Qp = 9 x Cu x Ap
Daya Dukung Ujung untuk Tanah Pasiran φφφφ
�Tiang Pancang :
Qp = 40 x N SPT x Ap
Dimana,N–SPT = (N1+N2)/2
N1= harga rata-rata N dari dasar ke 10-D keatasN2= harga rata-rata N dari dasar ke 4-D kebawah
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Nilai N – SPT Desain
adalah:
Ndesain = ½ (N1 +N2)
NILAI N – SPT UNTUK DESIGN TAHANAN UJUNG PADA TANAH PASIRAN φ :
D
(4 x D) dirata-rata untuk desain tahanan ujung = N2
(10 x D) dirata-rata untuk desain tahanan ujung = N1
Ground Sur face
Tiang Pancang
Daya Dukung Ujung untuk Tanah Pasiran Tiang BorTiang BorTiang BorTiang Bor
=7 N (t/m2)
=400 (t/m2)
qp = 7 N (t/m2) < 400 (t/m2)
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Daya Dukung Ujung Tiang Bor Tanah Pasiran φ:
Qb = σ σ σ σv.Nq.Ab
Kulhawy, 1983
DAYA DUKUNG AKSIAL
Qu = Qp + Qs
Qp
Qs =Σ2πr ∆l (α C)
+ Σ2πr ∆l (k σv tanδ)
.S.F
QQ u
all =
=Ap(c Nc +q Nq)
∆l
σv
κ σv
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Summary
τ
qp
Clay Sand
Pancang PancangTiang Bor Tiang Bor
αααα C αααα C
Untuk PancangAPI
Untuk Tiang BorKulhawy, 84Reese, 88
0.2 N
(Meyerhof)
0.2 N
(Rata2 antaraMeyerhof, 76 danReese+Wright, 77)
9999 C40 N
< 1600 t/m2
N=(N1+N2)/2
7 N (t/m2) < 400 (t/m2)
(Reese+Wrihgt, 77) (Meyerhof)
Pult = 2πr Σ ∆l τ + πr2 qp
Faktor Adhesi (α) pada Tanah Kohesif untuk
“Tiang Pancang” :
1. API Metode - 2, 1986
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Faktor Adhesi (α) pada Tanah Kohesif untuk
“Tiang Bor” :
1. Reese and Wright, 1977 :Manurut Reese dan Wright koefisien αααα untuk bored pile adalah 0.55
2. Kulhawy, 1984( k N / m )
U n d r a in e d S h e a r in g R e s is t a n c e , s ( t s f )
Ad
hesio
n f
acto
r (
)
α
T o m l in s o n , 1 9 5 7 ( c o n c r e t e p ile s )
6 5 U 8 4 1 C lo a d t e s t s
= 0 . 2 1 + 0 .2 6 p / s ( < 1 )
u
α a u
S h a f t s in c o m p r e s s io n
S h a f t s in u p l i f t
2
D a t a g r o u p 1
D a t a g r o u p 2
D a t a g r o u p 3
D a t a g r o u p 3
D a t a g r o u p 2
D a t a g r o u p 1
D
(4 x D)dirata-rata untukdesain tahanan ujung = N2
(10 x D)dirata-rata untukdesain tahanan ujung = N1
Ground Surface
Tiang Pancang
Ndesain = ½ (N1 +N2)
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SF Criterion Based on Canadian Foundation Engineering Manual (1992)
SF Criterion Based on Tomlinson (1977)
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Lensa Pada Group Tiang:
(Tomlinson, 1977)
Ketebalan Lapisan Tanah Yang Harus Diperhitungkan Dalam
Perhitungan Daya Dukung :
3-4B
a=4B
b=6-8 B
Minimal kedalaman penyelidikan tanah adalah sampai 4 diameter tiang (atau 5 m) dibawah dasar pondasi
3-4B
a=4B
b=6-8 B
3-4B3-4B
a=4B
b=6-8 B
Minimal kedalaman penyelidikan tanah adalah sampai 4 diameter tiang (atau 5 m) dibawah dasar pondasi
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Cross section of Soil Investigation
28.20
R1
32.20
R2
36.95
R5
36.9738.2038.20
R5 R5
38.20
R5 R2 R1
38
20
2221
78
4488
47
21
29
2734
24
1918
27
3224
23
22
41
25
1921
BT-2
18
20
33
22
22
24
19
18
17
18
50
37
BH-201
3
10
5
31.0036.95
R1 R3R2
38.20 38.2031.00
R4R4
43.20
R5R3
38.20 36.95
R2R5
38.20
R1
66
32
26
30
16
80
88
36
29
27
50
3334
45
912
32
54
62
60
39
33
50
18
26
21
90
8
6
10
10
6
BT-1
Proposed Additional Soil Investigation
Proposed Additional Soil Investigation
BH-201 BT-02
BT-01BH-202
Qult = 1610 ton
East Side (STA 1+050)
45m
Bored Pile Diameter 1,5m, panjang 45m
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Very stiff
Very stiff
Very stiff
Soft
Hard
Hard
Dense
Dense
Axial Capacity of Single Bored PileBased on Data at Sta 1+050
Positive Qbαααα Cu As or 0.2N As (Ton)
1 0.0 - 2.0 2.02 2.0 - 6.0 4.0 Clayey Silts 3 2.0 0.80 1.6 30.8 31 77.3 108.1 433 6.0 - 9.0 3.0 Clayey Sand 10 25 4.0 14.1 45 218.8 263.7 1054 9.0 - 11.5 2.5 Clayey Sand 37 30 14.8 43.6 88 618.5 707.0 2835 11.5 - 12.5 1.0 Sandstone 80 40 20.0 23.6 112 356.9 468.9 1886 12.5 - 15.0 2.5 Clayey Silts 33 22.4 0.46 10.3 121.6 234 237.9 471.6 1897 15.0 - 19.0 4.0 Clayey Silts 22 15.0 0.49 7.3 137.5 371 162.2 533.4 2138 19.0 - 22.0 3.0 Silty Clay 15 10.2 0.53 5.4 75.9 447 299.2 746.2 2989 22.0 - 30.0 8.0 Silty Clay 21 14.3 0.49 7.0 264.6 712 302.8 1014.4 40610 30.0 - 32.0 2.0 Silty Clay 39 26.5 0.45 12.0 112.9 824 245.1 1069.6 42811 32.0 - 33.0 1.0 Silty Clay 23 15.6 0.48 7.6 35.7 860 248.7 1108.9 44412 33.0 - 34.0 1.0 Silty Clay 22 15.0 0.49 7.3 34.4 895 270.4 1164.9 46613 34.0 - 35.0 1.0 Silty Clay 23 15.6 0.48 7.6 35.7 930 288.4 1218.6 48714 35.0 - 36.0 1.0 Silty Clay 24 16.3 0.48 7.8 37.0 967 299.2 1266.4 50715 36.0 - 37.0 1.0 Silty Clay 28 19.0 0.47 8.9 42.2 1009 274.0 1283.3 51316 37.0 - 38.0 1.0 Silty Clay 28 19.0 0.47 8.9 42.2 1051 259.6 1311.0 52417 38.0 - 39.0 1.0 Silty Clay 27 18.4 0.47 8.7 40.9 1092 227.1 1319.4 52818 39.0 - 40.0 1.0 Silty Clay 21 14.3 0.49 7.0 33.1 1125 237.9 1363.3 54519 40.0 - 41.0 1.0 Silty Clay 21 14.3 0.49 7.0 33.1 1158 248.7 1407.2 56320 41.0 - 42.0 1.0 Silty Clay 23 15.6 0.48 7.6 35.7 1194 302.8 1497.0 59921 42.0 45.0 3.0 Silty Clay 28 19.0 0.47 8.9 126.5 1321 254.2 1574.8 63022 45.0 - 47.0 2.0 Silty Clay 28 19.0 0.47 8.9 84.3 1405 205.5 1610.4 64423 47.0 - 50.0 3.0 Silty Clay 19 12.9 0.50 6.5 91.4 1496 227.1 1723.5 68924 50.0 - 55.5 5.5 Silty Clay 21 14.3 0.49 7.0 181.9 1678 1618.5 3296.8 131925 55.5 - 60.5 5.0 Silty sand 60 40 20.0 116.6 1795 1618.5 3413.4 1365
No. DepthTebal
Lapisan (m)Deskripsi Qult (Ton)
Qall (ton) SF = 2.5
Pile Cap
Skin Friction (ton)Kumulatif
Friction (ton)
End Bearing (ton)ααααN-SPT c (t/m2) φφφφ
Unit Skin Frinction
(t/m2)
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Medium stiff
Stiff
Hard
Very Hard
Hard
Very stiff
Dense
Dense
Axial Capacity of Single Bored PileBased on Data at Sta 0+490
Flyover CirebonSkin Friction (ton)
Positive Qbαααα Cu As or 0.2N As (Ton)
1 0.0 - 3.0 3.0 Clayey Silts 8 5.2 0.55 40.1 40 82.7 122.8
2 3.0 - 6.0 3.0 Clayey Silts 8 5.2 0.55 40.1 80 82.7 162.8
3 6.0 - 9.0 3.0 Clayey Silts 8 5.2 0.55 40.1 120 103.4 223.6
4 9.0 - 11.6 2.6 Clayey Silts 12 7.8 0.49 47.0 167 737.8 905.0
5 11.6 - 12.9 1.3 Tuffaceous Sand 90 35 30.6 198 450.8 648.7
6 12.9 - 17.0 4.1 Silty Sand 22 30 42.5 240 320.5 560.8
7 17.0 - 24.0 7.0 Silty Clay 31 20.2 0.43 284.2 525 620.3 1144.8
8 24.0 - 30.2 6.2 Tuffaceous Silt 60 39.0 0.41 460.9 985 408.3 1393.8
9 30.2 - 31.0 0.9 Tuffaceous Silt 45 29.3 0.41 48.6 1034 389.4 1423.4
10 31.0 - 32.0 1.0 Tuffaceous Silt 34 22.1 0.42 44.1 1078 351.5 1429.7
11 32.0 - 33.0 1.0 Tuffaceous Silt 34 22.1 0.42 44.1 1122 351.5 1473.8
12 33.0 - 34.0 1.0 Tuffaceous Silt 33 21.5 0.43 43.0 1165 341.1 1506.4
13 34.0 - 35.0 1.0 Tuffaceous Silt 33 21.5 0.43 43.0 1208 341.1 1549.4
14 35.0 - 36.0 1.0 Tuffaceous Silt 34 22.1 0.42 44.1 1252 351.5 1603.9
15 36.0 - 37.0 1.0 Tuffaceous Silt 36 23.4 0.42 46.5 1299 372.2 1671.1
16 37.0 - 38.0 1.0 Tuffaceous Silt 38 24.7 0.42 48.9 1348 392.8 1740.7
17 38.0 - 39.0 1.0 Tuffaceous Silt 27 17.6 0.43 35.9 1384 279.1 1662.8
18 39.0 - 40.0 1.0 Tuffaceous Silt 29 18.9 0.43 38.2 1422 299.8 1721.7
19 40.0 - 41.0 1.0 Tuffaceous Silt 29 18.9 0.43 38.2 1460 299.8 1759.9
20 41.0 - 42.6 1.6 Tuffaceous Silt 30 19.5 0.43 63.1 1523 237.8 1761.0
21 42.6 - 46.0 3.4 Tuffaceous Silt 23 15.0 0.44 105.8 1629 237.8 1866.8
22 46.0 - 46.0 0.0 Tuffaceous Silt 23 15.0 0.44 0.0 1629 620.3 2249.3
N-SPT c (t/m2) φφφφ ααααNo. DepthTebal
Lapisan (m)Deskripsi Kumulatif
Friction (ton)Qult (Ton)
End Bearing (ton)
2.41.0
45.0
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29 25 15 0.5 7.5 112.5 108 175 242
27 20 12 0.5 6.0 30 144 210 300
314 430
Prediksi Daya Dukung Tiang PancangTambak Lorok
rope and pulley (bukan free falling)
Based on Bored P-0 1.20
Skin Friction End Bearing
0.01 0.0 - 1.0 1.0 Silty Gravel 0 0.0 1.00 0.0 0 0 02 1.0 - 2.0 1.0 Silty Gravel 0 0.0 1.00 0.0 0 0 03 2.0 - 3.0 1.0 Silty sandy clay 5 3.0 0.80 9.0 9 31 404 3.0 - 4.0 1.0 Silty sandy clay 5 3.0 0.80 9.0 18 31 495 4.0 - 5.0 1.0 Silty sandy clay 7 4.2 0.62 9.8 28 43 716 5.0 - 6.0 1.0 Silty sandy clay 11 6.6 0.26 6.5 34 67 1027 6.0 - 7.0 1.0 Silty sandy clay 11 6.6 0.26 6.5 41 67 1088 7.0 - 8.0 1.0 Medium - Stiff clay 6 3.6 0.71 9.6 50 37 879 8.0 - 9.0 1.0 Medium - Stiff clay 20 12.0 0.40 18.1 69 122 19110 9.0 - 10.0 1.0 Tuffaceous 20 12.0 0.40 18.1 87 122 20911 10.0 - 11.0 1.0 Tuffaceous 31 18.6 0.40 28.0 115 189 30414 11.0 - 12.0 1.0 Tuffaceous 60 36.0 0.40 54.3 169 366 53515 12.0 - 13.0 1.0 Tuffaceous 60 36.0 0.40 54.3 223 366 59016 13.0 - 14.0 1.0 Tuffaceous 37 22.2 0.40 33.5 257 226 48317 14.0 - 15.0 1.0 Tuffaceous 48 28.8 0.40 43.4 300 293 59318 15.0 - 16.0 1.0 Tuffaceous 51 30.6 0.40 46.1 346 311 65819 16.0 - 17.0 1.0 Tuffaceous Silty sand with Gravel 51 30.6 0.40 46.1 392 311 70420 17.0 - 18.0 1.0 Tuffaceous Silty sand with Gravel 57 34.2 0.40 51.6 444 348 79221 18.0 - 19.0 1.0 Tuffaceous Silty sand with Gravel 62 37.2 0.40 56.1 500 379 87922 19.0 - 20.0 1.0 Tuffaceous Silty sand with Gravel 62 37.2 0.40 56.1 556 379 93523 20.0 - 21.0 1.0 Tuffaceous Silty sand with Gravel 54 32.4 0.40 48.9 605 330 93524 21.0 - 22.0 1.0 Tuffaceous Silty sand with Gravel 54 32.4 0.40 48.9 654 330 98425 22.0 - 23.0 1.0 Tuffaceous Silty sand with Gravel 60 36.0 0.40 54.3 708 366 107526 23.0 - 24.0 1.0 Tuffaceous Silty sand with Gravel 60 36.0 0.40 54.3 763 366 112927 24.0 - 25.0 1.0 Tuffaceous Silty sand with Gravel 51 30.6 0.40 46.1 809 311 112028 25.0 - 26.0 1.0 Tuffaceous Silty sand with Gravel 51 30.6 0.40 46.1 855 311 116629 26.0 - 27.0 1.0 Tuffaceous Silty sand with Gravel 39 23.4 0.40 35.3 890 238 112830 27.0 - 28.0 1.0 Tuffaceous silt very stiff 39 23.4 0.40 35.3 925 238 116431 28.0 - 29.0 1.0 Tuffaceous silt very stiff 47 28.2 0.40 42.5 968 287 125532 29.0 - 30.0 1.0 Tuffaceous silt very stiff 47 28.2 0.40 42.5 1010 287 129733 30.0 - 31.0 1.0 Gravel with sand noncemented 60 12 45.2 1056 452 150834 31.0 - 32.0 1.0 Gravel with sand noncemented 60 12 45.2 1101 452 155335 32.0 - 33.0 1.0 Tuffaceous silty sand very stiff 30 18.0 0.40 27.1 1128 183 131136 33.0 - 34.0 1.0 Tuffaceous silty sand very stiff 35 21.0 0.40 31.7 1160 214 137337 34.0 - 35.0 1.0 Tuffaceous silty sand very stiff 35 21.0 0.40 31.7 1191 214 140538 35.0 - 36.0 1.0 Tuffaceous silty sand very stiff 42 25.2 0.40 38.0 1229 257 1486
Maximum end bearing 400 ton/m2
N-SPT c (t/m2) ττττααααα α α α Cu As or
0.2N As
KsNo. DepthTebal
Lapisan (m)
Deskripsi
C N atau qNq Ap
Meyerhof
Kumulatif Friction (ton)
Qult (Ton)
Bored Pile Kiara Condong
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Pelaksanaan Bored Pile
Pelaksanaan Bored Pile
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Pelaksanaan Bored Pile
Slurry Method
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Casing Method
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Method Statement of Bored Pile
Casing Installation Drilling Process Cleaning at Final Depth
Reinforcement Installation
Pouring Concrete Temporary CasingRemoval
Bored Piling Method of Works
Drilling tools
Auger Cleaning bucket
Underreamer
Roller bit core barrel
Drill Bucket
Round shank Core BarrelTapered rock auger
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Sambungan Tiang Pancang
Sambungan Tiang Pancang
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Spesifikasiend bearing = 1 in/ 10 blows
Final Set = ? In/10 blows
Analisis Daya Dukung Berdasarkan Persamaan
Gelombang
A = cross-sectional area of pile Cm = relative displacement between two
adjacent pile elements
D?m = element displacement two time intervals back m
D?m = element displacement in preceding time interval DT m
Dm = current element displacement
DT = time interval (At on Error! Reference source not found.c) E = modulus of elasticity of pile material Fm = element force = Cm Km Fam = unbalanced force in element causing acceleration (F = ma)
g = gravitation constant J = damping constant, use Js for side
value, Jp = point value Km = element springs = AE/L for pile
segments K?m = soil springs = R/quake
L = length of pile element Rm = side or point resistance including
damping effects R?m = amount of estimated Pu on each
element including the point j for 100
m percent of Pu on point R3 through R11 of Error! Reference source not found.b are zero and R12 = Pu
t = current instant in time = number of iterations x DT
v = velocity of element m at DT
v?m = velocity of element m at DT - 1 Wm = weight of pile segment m
03/03/2012
34
Formula Dinamik ENR
CS
hWQu R
+⋅=
atau
CS
HEQu E
+= .
dimana:
Qu : Kapasitas daya dukung ultimateWR : Berat ram (kN)h : Tinggi jatuh ram (cm)S : Penetrasi tiang untuk setiap pukulan(m/blow)C : konstanta, untuk drop hammer = 2.54 cm, untuk steam hammer = 0.254 cmAngka keamanan yang direkomendasikan adalah 6.
Modified New ENR (recommended)
++
+=
PR
pRR
WW
WnW
CS
hWEQu
2..
dimana:
E : Efisiensi hammer C : 0.254 cm untuk unit S dan h dalam centimeter Wp : Berat tiang
n : koefisien restitusi antara ram dan pile cap Angka keamanan yang direkomendasikan adalah 6.
03/03/2012
35
Harga Efisiensi Hammer (E)dan Koef. Restitusi (n)
Tipe Hammer Efficiency, E
Single and Double acting hammer 0.7 – 0.8
Diesel Hammer 0.8 – 0.9 Drop Hammer 0.7 – 0.9
Pile Material Coefficient of restitution, n
Cast iron hammer and concrette pile (whitout cap) 0.4 – 0.5
Wood cushion on steel pile 0.3 – 0.4 Wooden pile 0.25 – 0.3
Michigan State Highway Commission
++
+=
PR
pRE
WW
WnW
CS
HQu
25.2
dimana:
HE : Rated hammer energy (from the factory) C : 0.254 cm Angka keamanan yang direkomendasikan adalah 6.
03/03/2012
36
Dannish’s Formula
+=
pp
E
E
EA
LHES
HEQu
..2
..
.
dimana:
Ep : Modulus Young dari material tiang
L : Panjang tiang Ap : Luas penampang tiang Angka keamanan yang direkomendasikan bervariasi dari 3 hingga 6.
Analisis Daya Dukung Berdasarkan Persamaan Gelombang
A = cross-sectional area of pile Cm = relative displacement between two
adjacent pile elements
D?m = element displacement two time intervals back m
D?m = element displacement in preceding time interval DT m
Dm = current element displacement
DT = time interval (At on Error!
Reference source not found.c) E = modulus of elasticity of pile material Fm = element force = Cm Km
Fam = unbalanced force in element causing acceleration (F = ma)
g = gravitation constant J = damping constant, use Js for side
value, Jp = point value
Km = element springs = AE/L for pile segments
K?m = soil springs = R/quake
L = length of pile element Rm = side or point resistance including
damping effects R?m = amount of estimated Pu on each
element including the point j for 100
m percent of Pu on point R3 through
R11 of Error! Reference source not found.b are zero and R12 = Pu
t = current instant in time = number of
iterations x DT v = velocity of element m at DT
v?m = velocity of element m at DT - 1 Wm = weight of pile segment m
03/03/2012
37
Contoh Perhitungan
Diameter PC Spun Pile : 400 mmBerat Tiang Per m : 200 kgBerat hammer pemancang : 3,45 (K – 35)Tinggi Jatuh : 1,60 mDaya Dukung Ultimate yang diinginkan : 210 ton.Daya Dukung Ijin yang diinginkan : 50 ton.
Perhitungan Final set :
SF = 6 ���� ultimated bearing Capacity = 300 ton.
Contoh Perhitungan
1. Menggunakan Modified ENR Formula
pR
pRRu WW
WnW
CS
WEQ
++
×+
=2
.
cms
s
s
S
xs
S
x
248,0
)08,523(2106
82,119,5342106
783.102,782,11
300
)02,7()254.0(
82,11300
6,342,3
6,35.042,3
254.0
42,38,0300
2
−=−=
=++
=
+=
++×
+=
Final Set adalah 0,248 cm/blow ���� 2,48 cm/10 blows.
03/03/2012
38
Contoh Perhitungan
2. Menggunakan formula dari Michigan state Highway Commision (1965)
Final Set adalah 0,225 cm/blow ���� 2,25 cm/10 blows.
pR
pREu WW
WnW
CS
HQ
++
×+×=
25.2
cms
s
ss
s
S
2258,0
)74,67(300
461,82,76300254.0
461,8300
6154.0254.0
75.13300
6,342,3
6,35,042,3
254.0
5,55.2300
2
−=−=
=++
=
×+
=
++×
+×=
Contoh Perhitungan
3. Menggunakan formula Danish
Final Set adalah 0,03 cm/blow ���� 0,3 cm/10 blows.
pp
E
Eu
EA
LHES
HEQ
.2
..+
=
blowcms
s
sS
S
S
/03,0
025,9300
75,2775,113000392.075,2
300
321300095,4
75,2300
10.1,20765,02185,55,0
5,55.0300
7
=−=
=++
=
+=
××××+
×=
03/03/2012
39
UJI BEBAN STATIS DAN
INTERPRETASINYA
Uji Beban :� Uji beban pendahuluan (preliminaries test )
dengan instrumentasi sampai kegagalan� Uji beban pembuktian (proof test )
Sampai 200% beban rencana, 100% atau kurang
Uji Beban Statis dan Interpretasinya (1)
Uji Beban :� Slow ���� Slow maintained test (cyclic)� Quick : Quick maintained load
Constant rate of penetration (CRP)
Prinsip Interpretasi :� Batas penurunan� Rate of settlement (kecepatan penurunan)� Kegagalan didefinisikan dari bentuk kurva load & deformation
Uji Beban Tiang (tekan)
03/03/2012
40
Uji Beban Statis dan Interpretasinya (2)
Interpretasi uji beban :�Cara Davisson�Cara Mazurkiewics�Cara Chin
Kurva load vs settlement uji beban siklik
0
5
10
15
20
25
30
350 200 400 600 800 1000 1200 1400 1600
APPLIED LOAD (TONS)
SE
TT
LE
ME
NT
(M
M)
Cycle 1 Cycle 2 Cylce 3Cylce 4 Cycle 5 Cycle 6
03/03/2012
41
0
5
10
15
20
25
30
35
0 200 400 600 800 1000 1200 1400 1600
APPLIED LOAD (TONS)
SE
TT
LE
ME
NT
(M
M)
Cara Davisson
Metode Davisson
EA
QLe =δ
12015,0
Dx += inch
dimana �e = penurunan elastis Q = beban uji yang diberikan L = panjang tiang A = luas penampang tiang E = modulus elastisitas tiang
XQult = 1415 ton
Cara Mazurkiewics
03/03/2012
42
y = 0.0006x + 0.0036
0
0.005
0.01
0.015
0.02
0.025
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00
SETTLEMENT (mm)
SE
TT
LE
ME
NT
/LO
AD
(m
m/t
on
)Cara Chin
Metode Chin
21 CCQ
+⋅= δδ
1
1
CQu =
Qu koreksi = 0,8 Qu
1/Qult = 0,0006 Qult = 1666,67 ton Faktor reduksi = 20 % Qult koreksi = 1333 ton
C2
0
5
10
15
20
25
0 200 400 600 800 1000 1200 1400 1600
Loads (ton)
Set
tlem
ent
(mm
)
Cara Davisson untuk cylce ke-6
Qult = 1505 ton
03/03/2012
43
Cara Chin untuk cycle ke-6
y = 0.0005x + 0.0036
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0 5 10 15 20 25
Settlement (mm)
Set
tlem
ent/
Lo
ad (
mm
/to
n)
1/Qult = 0,0005 Qult = 2000 ton Faktor reduksi = 20 % Qult koreksi = 1600 ton
NEGATIVE SKIN FRICTION :�Terjadi kondisi dimana Pondasi direncanakan akan dipancang sampai
lapisan tanah keras sementara tanah di atasnya adalah lapisan kompresibel,
yang di atasnya terdapat timbunan. Tanah kompresibel ini akan mengalami
konsolidasi akibat adanya pertambahan beban timbunan. Selama proses
konsolidasi ini tanah akan bergerak relatif terhadap tiang. Sehingga,
menghasilkan tahanan geser ke bawah di sekeliling tiang
03/03/2012
44
NEGATIVE SKIN FRICTION :
Daerah Negative Skin Friction
Fill material
Soft soil,Consolidating soil
Bearing soil
03/03/2012
45
METODA PERHITUNGAN NEGATIVE SKIN FRICTION :� Negative Skin Friction pada Kondisi Un-Drained :
dimana,
α = faktor adhesi
Cu = undrained shear strength dari nilai N – SPT
Ks = Koeffisien lateral earth pressure.
δ = interface sudut geser dalam antar tiang dan tanah.
σv = effective overbourden pressure.
Prakash dan Sharma, 1990
( )zKsCu
P
vdiameterpile
LbLcLfx
LcLfxutseareafriction
∆Σ+Σ=
Ψ= ∑++=
+=
δσαπφ
τ
tan5,0
lim
tanah lempung tanah pasir
03/03/2012
46
METODA PERHITUNGAN NEGATIVE SKIN FRICTION :� Negative Skin Friction pada Kondisi Drained :
dimana,
σo’ = Effective vertical stress at depth z
f = pile diameter
Le = panjang effective dari lapisan yang terkonsolidasi yang menimbulkannegative skin friction. Lc = 0.75 Le
No = Non dimensional factor.
∫
∫+=
=
+=
=
∆××××=
∆×××=
LeLfz
z
LeLfz
z
negatif
zRN
zRQf
0
00
0
)(
πσ
πτ
Prakash dan Sharma, 1990
METODA PERHITUNGAN NEGATIVE SKIN FRICTION :
� Non – dimensional factor (No):
Prakash dan Sharma, 1990
Soil Type No
a. Uncoated Pile
- Sand 0.35 – 0.50
- Silt 0.25 – 0.35
- Clay 0.20 – 0.25
b. Coated Pile with Bitumen SL pile : τ = 0.2 ton/m2
� Alternative Pelapisan Bitument :
- Untuk mengurangi pengaruh terjadinya konsolidasi tanah lunak akibat timbunan
di atasnya bisa diupayakan dengan melakukan pelapisan bitument asphalt pada
tiang pancang sebelum dilakukan pemancangan.
- Pelapisan bitument dilakukan sepanjang lapisan lunak yang mengalami konsoli-
dasi.
- Dengan pelapisan bitument tersebut, negative skin friction yang terjadi bisa di-
minimasi.
03/03/2012
47
KAPASITAS IJIN TIANG YANG MENGALAMI NEGATIVE
SKIN FRICTION (NSF):
Prakash dan Sharma, 1990
SF
NSFultimateijin
−= σσ
atau
NSFSFultimate
ijin −= σσ
� SF berkisar antara 2,0 – 3,0
03/03/2012
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Pile Group Efficiency
Salah satu perilaku tiang group adalah ada group efficincy yang Berhubunan dengan parak tiang tunggal dalam group tiang:
(Nav Doc, September 1986)
03/03/2012
49
Pile Group Efficiency• CONVERSE – LABARRE FORMULA• (n-1)m + (m-1)n• Ŋ = 1 - ξ { ------------------------- } / 90• m n
• Ŋ = Factor Effisiensi Group• ξ = arc tan d/s (in degree)• m = jumlah baris• n = jumlah pile pada satu baris• d = diameter tiang • s = jarak antara tiang ke tiang
• l
m = 2 , n = 3 , d= 30 cm s=120 cm
ξ = arc tan 30/120
s
Transfer beban pada Group Tiang:
(Tomlinso, 1977)
03/03/2012
50
Settlement Analysis
Consolidation Settlement
03/03/2012
51
∆σ
Seluruh dipikul air
∆σ Seluruh dipikul Tanah
∆σ
∆σ∆σ
U + ∆σ U
S
pegas(tanah)
kecepatan air ditentukan permeabilitas
air
0 0
∆σ 0
PEMODELAN KONSOLIDASI PRIMER
Akibat pertambahan beban � kenaikan tekanan air pori
Keluarnya air dari pori � tekanan air pori kembali lagi (tanah settle)
Kurva Test Konsolidasi
03/03/2012
52
Persamaan untuk Menghitung Penurunan Konsolidasi (Normally Consolidated Clay)
o
avo
o
cc
p
p∆plog
e1
HC
++
Dimana,
p0 = tekanan efektif akibat berat sendiri
∆∆∆∆pav = tambahan tekanan efektif akibat beban diatas lapisan kompresible
e0 = initial void ratio
Cc = compression index
Hc = tebal lapisan lempung
Calculation of Settlement (STA 0+490)
γ γ γ γ ' σσσσ'b σσσσ'm ∆σ∆σ∆σ∆σ σσσσ1 =σσσσo+∆∆∆∆s Cc eo ∆∆∆∆s
(t/m3) (t/m
2) (t/m
2) (t/m
2) (t/m
2) (m)
1 0.0 - 3.0 3.02 3.0 - 6.0 3.03 6.0 - 9.0 3.04 9.0 - 11.6 2.65 11.6 - 12.9 1.36 12.9 - 17.0 4.17 17.0 - 24.0 7.08 24.0 - 26.5 2.5
9 26.5 30.0 3.510 30.0 - 33.0 3.0 0.7 2.1 1.1 4.04 5.1 0.05 0.6 0.0611 33.0 - 36.0 3.0 0.7 4.2 3.2 3.03 6.2 0.05 0.6 0.0312 36.0 - 39.0 3.0 0.7 6.3 5.3 2.36 7.6 0.05 0.6 0.0213 39.0 - 42.0 3.0 0.7 8.4 7.4 1.89 9.2 0.05 0.6 0.0114 42.0 - 44.0 2.0 0.7 9.8 9.1 1.65 10.8 0.07 0.55 0.0115 44.0 - 46.0 2.0 0.7 11.2 10.5 1.46 12.0 0.07 0.55 0.01
0.13AB Value Correction 0.7
0.09
No. DepthTebal
Lapisan (m)
Settlement (m)
Settlement (m)
31.5x0.7=22.0534.5x0.7=24.1537.5x0.7=26.2540.5x0.7=28.3543.0x0.7=30.1045.0x0.7=31.50
σσσσo”
26.0927.1828.6130.2431.7532.96
0.0070.0050.0040.0030.0020.0020.023
03/03/2012
53
Contoh-Contoh Pemilihan Jenis Pondasi
Location of Soil Investigation
S-3
S-1
S-2
S-4
S-5
S-6
03/03/2012
54
Soil ProfileBH 1.0 (EL+0.473) BH 1.1 (EL+0.582) BH 1.2 (EL+1.895)
BH 1.0 (EL+0.473) BH 1.1 (EL+0.582) BH 1.2 (EL+1.895) BH 1.3 (EL+0.942) BH 1.4 (EL+0.415)
SPUN PILE PENETRATIONWITHOUT PRE-AUGER
SPUN PILE PENETRATIONWITH PRE-AUGER
PIPE PILE PENETRATION
ESTIMATED MAXIMUM
ESTIMATED MAXIMUM
ESTIMATED MAXIMUM STEEL
(Ø = 600 mm, thickness = 140 mm)
Figure 8 - Estimated Maximum Length of Pile Penetration (Tank-1)Maximum penetration for precast concrete pile
Without preauger
With preauger
03/03/2012
55
BH 2.0 (EL+0.657) BH 2.1 (EL+0.406) BH 2.2 (EL+1.807) BH 2.3 (EL+1.987) BH 2.4 (EL+1.060)
WITHOUT PRE-AUGERSPUN PILE PENETRATIONESTIMATED MAXIMUM
ESTIMATED MAXIMUMSPUN PILE PENETRATIONWITH PRE-AUGER
ESTIMATED MAXIMUM STEELPIPE PILE PENETRATION(Ø = 600 mm,thickness = 140 mm)
Figure 9 - Estimated Maximum Length of Pile Penetration (Tank-2)
BH 1.0 (EL+0.473) BH 1.1 (EL+0.582) BH 1.2 (EL+1.895) BH 1.3 (EL+0.942) BH 1.4 (EL+0.415)
SPUN PILE PENETRATIONWITHOUT PRE-AUGER
SPUN PILE PENETRATIONWITH PRE-AUGER
PIPE PILE PENETRATION
ESTIMATED MAXIMUM
ESTIMATED MAXIMUM
ESTIMATED MAXIMUM STEEL
(Ø = 600 mm, thickness = 140 mm)
Figure 8 - Estimated Maximum Length of Pile Penetration (Tank-1)
Maximum penetration for steel pipe pileRecommended thickness 16 mm
BH 2.0 (EL+0.657) BH 2.1 (EL+0.406) BH 2.2 (EL+1.807) BH 2.3 (EL+1.987) BH 2.4 (EL+1.060)
WITHOUT PRE-AUGERSPUN PILE PENETRATIONESTIMATED MAXIMUM
ESTIMATED MAXIMUMSPUN PILE PENETRATIONWITH PRE-AUGER
ESTIMATED MAXIMUM STEELPIPE PILE PENETRATION(Ø = 600 mm,thickness = 140 mm)
Figure 9 - Estimated Maximum Length of Pile Penetration (Tank-2)
BH 1.0 (EL+0.473) BH 1.1 (EL+0.582) BH 1.2 (EL+1.895) BH 1.3 (EL+0.942) BH 1.4 (EL+0.415)
SPUN PILE PENETRATIONWITHOUT PRE-AUGER
SPUN PILE PENETRATIONWITH PRE-AUGER
PIPE PILE PENETRATION
ESTIMATED MAXIMUM
ESTIMATED MAXIMUM
ESTIMATED MAXIMUM STEEL
(Ø = 600 mm, thickness = 140 mm)
Figure 8 - Estimated Maximum Length of Pile Penetration (Tank-1)Recommended foundation for large tension load
Bored pile
03/03/2012
56
PEMANCANGAN
Pemancangan menggunakan Pontoon Hammer dng minimum energy 6 ton.m
-16 lws
-12 lws
URUTAN PEMANCANGAN DAN ANCHORING
1 2 3 4 5
Pemancangan sampai batas maksimal yang dapat ditembus (5.0 m) menggunakan minimal K-60
•Pembersihan tanah / kotoran didalam pipa
•Pemboran tanah dalam pipa untuk anchor
•Pemasangan Ground anchor
•Grouting & Curing
•Penegangan kabel untuk kelurusan
•Pengecoran isi dalam tiang dengan menggunakan tremi, bucket cor diangkat menggunakan crane
•Pengecoran plat form dan curing
• Stresing kabel
•Pengecoran kepala anchor.
03/03/2012
57
5.0
0 m
5.0
0 m
6.30 m 5.00 m
7.00 m
DAMPAK PENGGALIAN TERHADAP
KESTABILAN TANAH
HASIL-HASIL PENYELIDIKAN TANAH (BH-355)
B.04
mixed with fines material
gravels & boulders andesite
KETERANGAN :
: Collovial deposit
B.03BH-355
B.05BH-355
G.W.L
TO JAKARTA
BH-355B.02
: Siltstone / claystone
G.W.L
0
1
3
5
10 M
G.W.L
BH-355
TO BANDUNG
B.01BH-355
z = 3.00 – 3.60
m
qu = 1.71
kg/cm2
c = 0.082
kg/cm2
φ = 80
qc = 5 kg/cm2
z = 3.50 – 4.00
m
qu = 1.1 kg/cm2
c = 0.482
kg/cm2
φ = 230
qc = 25 kg/cm2
03/03/2012
58
TIPIKAL BENTUK PIER
Tampak Atas
Tampak Samping Tampak Depan
Transfer beban pada Group Tiang:
(Tomlinso, 1977)
03/03/2012
59
Berikut ini adalah jarak Pile agar effiency group
menjadi optimal :
(Tomlinson, 1977)
Berikut ini adalah jarak Pile agar effiency group
menjadi optimal :
(Tomlinson, 1977)
03/03/2012
60
P existing tunggal pada Pile Group
8
2
4 5 6
7
1
9
3
X
Y
My
Mx
X
Y
P existing tunggal pada Pile Group
P Group My . X Mx . Y
P singgle = --------------- + --------------------- + -----------------
N Σ X 2 Σ Y 2
P Singgle = Gaya Aksial yang bekerja pada tiang tunggal di koord ( x , y )
P Group = Gaya Aksil yang bekerja pada Pile Group
N = Jumlah Tiang pada Pile Group
My = Momen yang bekerja pada Pile Group arah sumbu y
Mx = Momen yang bekerja pada Pile Group arah sumbu x
X & Y = Koordinat P singgle yang akan dicari Gayanya
Σ X 2 & Σ Y 2 = Jumlah dari jarak koordinat kwadrat sumbu x dan sumbu y
03/03/2012
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Pile No Sum P/n Xi Yi My X/Σxi2 Mx Y/Σyi2 Force Ext.
ton cm cm ton
1 23.6988 -400 400 -13.2124 0.3900 10.8763
2 23.6988 0 400 0.0000 0.3900 24.0888
3 23.6988 400 400 13.2124 0.3900 37.3012
4 23.6988 -400 0 -13.2124 0.0000 10.4864
5 23.6988 0 0 0.0000 0.0000 23.6988
6 23.6988 400 0 13.2124 0.0000 36.9112
7 23.6988 -400 -400 -13.2124 -0.3900 10.0964
8 23.6988 0 -400 0.0000 -0.3900 23.3088
9 23.6988 400 -400 13.2124 -0.3900 36.5213
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