piled foundation - pile capacity - skin resistance (q ) - sand · 31 * das (2016), principles of...
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand
31 * Das (2016), Principles of Foundation Engineering, 8th edition
Michael Tomlinson and John Woodward (2008), Pile Design and Construction Practice.
High-displacement driven = Large displacement piles
Low-displacement driven = Small displacement pilesBored or jetted = Replacement pilesCoyle and Castello (1981)
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand
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High displacement driven piles
Low displacement driven piles
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand - SPT
33 * Das (2016), Principles of Foundation Engineering, 8th edition
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand - CPT
34 * Das (2016), Principles of Foundation Engineering, 8th edition
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand - Example
* Das (2016), Principles of Foundation Engineering, 8th edition
= 6.1 m
f (z = 0) = 0
f (z = 6.1) = 75.9
f ( 6.1 < z < 20) = 75.9 constant (= 75.9) from 6.1 m to 20 m
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand - Example
* Das (2016), Principles of Foundation Engineering, 8th edition
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≃ 0.4
by projection
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand - Example
37 * Das (2016), Principles of Foundation Engineering, 8th edition
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Sand - Example - CPT
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Lamda (𝜆)
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Alpha (𝛼)
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Alpha (𝛼)0.25
This is shown graphically in Figure 9.21. For cuy !o9 $ 1,
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Beta (𝛽)
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Example
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cupa
= 0.25
cupa
= 0.4
cupa
= 0.9
↵ = 0.87
↵ = 0.51
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Example
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Example
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442 Chapter 9: Pile Foundations
Example 9.7Refer to the pipe pile in saturated clay shown in Figure 9.24. For the pile,
a. Calculate the skin resistance sQsd by (1) the ! method, (2) the " method, and (3) the # method. For the # method, use $R9 5 308 for all clay layers. The top 10 m of clay is normally consolidated. The bottom clay layer has an OCR 5 2. (Note: diameter of pile 5 457 mm)
b. Using the results of Example 9.2, estimate the allowable pile capacity sQalld. Use FS 5 4.
SolutionPart a(1) From Eq. (9.59),
Qs 5 o!cu pDL
Table 9.13 Typical Values of Angle of Friction $9 of Rocks
Type of rock Angle of friction, f9 (deg)
Sandstone 27–45Limestone 30–40Shale 10–20Granite 40–50Marble 25–30
Groundwatertable
A1 5 72
A2 5 512.16
A3 5 1392.8
z
(a) (b)20 m 180.23
98.3310 m
3 m48
!9o (kN/m2)
3 mSaturated clay
Clay7 m
10 m
Diameter 5457 mm
cu(2)"sat
5 40 kN/m2
5 17 kN/m3
cu(1)"
5 25 kN/m2
5 16 kN/m3
Claycu(3)"sat
5 90 kN/m2
5 18 kN/m3
Figure 9.24 Estimation of the load bearing capacity of a driven-pipe pile
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a MethodAccording to the
Piled Foundation - Pile Capacity - Skin Resistance (Qs) - Clay - Example
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Piled Foundation - Pile Capacity - Skin Resistance (Qs) - CPT
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Piled Foundation - Pile Capacity - Qp - Rock
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Piled Foundation - Pile Capacity - Negative Skin Friction
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Piled Foundation - Pile Capacity - Negative Skin Friction
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Piled Foundation - Pile Capacity - Negative Skin Friction - Example
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Piled Foundation - Pile Capacity - Negative Skin Friction - Example
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Piled Foundation - Group Piles - Group Efficiency
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Piled Foundation - Group Piles - Group Efficiency
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Piled Foundation - Group Piles - Group Efficiency
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Piled Foundation - Group Piles - Group Efficiency
lb to kip in to feet
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Piled Foundation - Group Piles - Group Efficiency
8 8.57
8.75