FOUNDATION DESIGNS
A. Preliminary
The foundation of the building is the most important construction in a building. Because the foundation serves as a barrier to all the loads (life and death) that are above it and style of force from the outside. The foundation is part of the structure that serves to continue the burden to the supporting ground layer below it. In any structure, the load occurring either due to the weight of itself or due to the load of the plan shall be channeled into a supporting layer in this case is the ground under the structure.
In the foundation there should be no decrease in the foundation of the foundation or even the uniform foundation over certain limits, namely:
In the foundation there should be no decrease in the foundation of the foundation or even the uniform foundation over certain limits, namely:
1. General building 2.54 cm
2. Factory building 3.81 cm
3. Warehouse 5.08 cm
4. Engine foundation 0.05 cm
2. Factory building 3.81 cm
3. Warehouse 5.08 cm
4. Engine foundation 0.05 cm
Many factors in the selection of the type of foundation, among others, planned load work, type of soil layer, and non-technical factors such as construction costs, and construction time. The type of foundation chosen should be able to guarantee the position of the structure of all working forces. In addition, the supporting ground must have sufficient carrying capacity to carry the work load so that no collapse occurs. In certain cases if it is not possible to use shallow foundations, deep foundations are used. The foundation in which is often used is pile foundation. According Bowles (1984), pile foundation is widely used in high-rise buildings that get lateral and axial loads. This type of foundation is also widely used in structures built on expanding soil (expansive soil). The carrying capacity of the pile obtained from the skin friction can be applied to withstand the uplift force that occurs. The erosion factor in the river is also a consideration of the use of piles on the bridge.
B. Count Analysis
Is known: Cohesion and Angle of internal ground friction = 15 KN/m2& 25o
Soil type = Sand
Fc’ = 40 Mpa = 400 kg/cm2
Fy = 240 Mpa = 2400 kg/cm2
Figure 3.1 Pieces of Piles
Foundation Pole:
1. In use diameter pole ø 40 cm, steel reinforcement 8 ø 16 m
2. Area of concrete
1. In use diameter pole ø 40 cm, steel reinforcement 8 ø 16 m
2. Area of concrete
Ac = ¼.π.d2
= ¼. 3,14. 402
= 1256 cm2
3. The area of steel reinforcement
As = ¼.π.d2. 8
= ¼. 3,14. 1,62. 8
= 16,077 cm2
4. Material capacity:
a. Pr = 0,85. f {0,85. fc’(Ac-As) + As.fy}
= 0,85. 0,7 {0,85.400(1256-16,077)+16,077.2400}
= 273794,3789 kg
= 273,794 ton
b. f = 0,7 for spiral stirrups
5. Capacity of land support:
Example of a depth of 5 m (sand)
Example of a depth of 5 m (sand)
Qc = 145 kg/cm2
Ft = 274 kg/cm
Sf 1 = 3 ;Sf 2 = 5
K = π.d = 3,14 . 40 = 125,6 cm
Qa = (Ap. qc)/SF1 + (k.ft)/SF2
= (1256 . 145) / 3 + (125,6. 274) / 5
= 67589,54kg = 67,59 ton
Table 3.1 Soil Sondir Data
Depth
|
qc
|
Ft
|
Qa
|
M
|
kg/cm2
|
kg/cm'
|
Kg
|
0,00
|
0
|
0,00
|
0
|
0,20
|
10
|
10,00
|
4437,86
|
0,40
|
5
|
20,00
|
2595,73
|
0,60
|
10
|
24,00
|
4789,54
|
0,80
|
15
|
34,00
|
7134,08
|
1,00
|
40
|
54,00
|
18103,14
|
1,20
|
115
|
64,00
|
49754,34
|
1,40
|
90
|
84,00
|
39790,08
|
1,60
|
60
|
104,00
|
27732,48
|
1,80
|
35
|
114,00
|
17517,01
|
2,00
|
40
|
124,00
|
19861,54
|
2,20
|
20
|
128,00
|
11588,69
|
2,40
|
25
|
138,00
|
13933,22
|
2,60
|
25
|
148,00
|
14184,42
|
2,80
|
25
|
156,00
|
14385,38
|
3,00
|
25
|
166,00
|
14636,58
|
3,20
|
21
|
174,00
|
13162,88
|
3,40
|
25
|
184,00
|
15088,74
|
3,60
|
35
|
204,00
|
19777,81
|
3,80
|
150
|
224,00
|
68426,88
|
4,00
|
160
|
244,00
|
73115,94
|
4,20
|
180
|
264,00
|
81991,68
|
4,40
|
145
|
274,00
|
67589,54
|
4,60
|
120
|
294,00
|
57625,28
|
4,80
|
145
|
304,00
|
68343,14
|
5,00
|
45
|
324,00
|
26978,88
|
5,20
|
45
|
354,00
|
27732,48
|
5,40
|
45
|
364,00
|
27983,68
|
5,60
|
31
|
382,00
|
22574,50
|
5,80
|
25
|
392,00
|
20313,70
|
6,00
|
20
|
402,00
|
18471,57
|
6,20
|
15
|
422,00
|
16880,64
|
6,40
|
30
|
442,00
|
23663,04
|
6,60
|
25
|
452,00
|
21820,90
|
6,80
|
20
|
462,00
|
19978,77
|
7,00
|
30
|
466,00
|
24265,92
|
7,20
|
35
|
476,00
|
26610,45
|
Figure 3.2 Cut Pile Foundation and Pile Position
|
Figure 3.3 Top View Foundation
6. Pile support capacity
a. Based on the load P = 202.06 tons
b. Based on land P = 67.59 tons
So the support capacity of pole permit = 67.59 tons In use P permit = 67 tons
c. The result of structural analysis on the ground floor column P = 2056,1 KN= 205.61 tons
d. Permit capacity P permit = 67 tons
e. Needs polen = P / Pijin = 205,61 / 67 = 3,069 used 4 pieces of pole
f. Distance pole min 2D
7. Load Control
· In base column P = 205,61 ton and My = 198,9 KN = 19,89 ton
Number of pole n = 4
<Pijin = 67 tons (fulfilling)
With the capacity of the foundation license (P permit) at 4.4 m deep.
a. Based on the load P = 202.06 tons
b. Based on land P = 67.59 tons
So the support capacity of pole permit = 67.59 tons In use P permit = 67 tons
c. The result of structural analysis on the ground floor column P = 2056,1 KN= 205.61 tons
d. Permit capacity P permit = 67 tons
e. Needs polen = P / Pijin = 205,61 / 67 = 3,069 used 4 pieces of pole
f. Distance pole min 2D
7. Load Control
· In base column P = 205,61 ton and My = 198,9 KN = 19,89 ton
Number of pole n = 4
<Pijin = 67 tons (fulfilling)
With the capacity of the foundation license (P permit) at 4.4 m deep.
Table 3.2 Checking The foundation of each qualified column
Kolom
|
P kolom (ton)
|
P ijin (ton)
|
My (ton.m)
|
n
|
P1
|
P2
|
Keterangan
|
K1
|
139,91
|
58
|
16,40
|
4
|
40,41
|
40,41
|
Memenuhi
|
K15
|
153,05
|
58
|
18,61
|
4
|
43,04
|
43,04
|
Memenuhi
|
K 8
|
140,93
|
58
|
15,98
|
4
|
40,61
|
40,61
|
Memenuhi
|
K 387
|
155,72
|
58
|
13,72
|
4
|
43,57
|
43,57
|
Memenuhi
|
K 394
|
155,93
|
58
|
13,57
|
4
|
43,61
|
43,61
|
Memenuhi
|
K282
|
156,56
|
58
|
11,78
|
4
|
43,74
|
43,74
|
Memenuhi
|
K296
|
205,61
|
58
|
13,63
|
4
|
53,55
|
53,55
|
Memenuhi
|
K289
|
156,35
|
58
|
11,86
|
4
|
43,70
|
43,70
|
Memenuhi
|
K401
|
150,55
|
58
|
19,89
|
4
|
42,54
|
42,54
|
Memenuhi
|
K408
|
150,30
|
58
|
10,19
|
4
|
42,49
|
42,49
|
Memenuhi
|
K317
|
148,99
|
58
|
19,13
|
4
|
42,22
|
42,22
|
Memenuhi
|
K331
|
200,13
|
58
|
10,62
|
4
|
52,45
|
52,45
|
Memenuhi
|
K324
|
150,41
|
58
|
9,30
|
4
|
42,51
|
42,51
|
Memenuhi
|
K415
|
147,65
|
58
|
11,19
|
4
|
41,96
|
41,96
|
Memenuhi
|
K422
|
165,42
|
58
|
11,40
|
4
|
45,52
|
45,52
|
Memenuhi
|
K352
|
126,37
|
58
|
11,41
|
4
|
37,71
|
37,71
|
Memenuhi
|
K366
|
202,06
|
58
|
13,16
|
4
|
52,84
|
52,84
|
Memenuhi
|
K359
|
175,71
|
58
|
11,10
|
4
|
47,57
|
47,57
|
Memenuhi
|
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