CHAPTER 2. PILING

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UFC 4-151-10

10 September 2001

CHAPTER 2

PILING

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GENERAL REQUIREMENTS

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Capacity

2-1.1.1

Capacity as a Structural Member. For pile sections embedded in the

sections freestanding in water, treat piles as structural columns with accommodation

made for their un-braced length. Where, due to long-term creep effects, the use of the

coefficient of sub-grade reaction would be inappropriate or if one is unavailable, the

following assumptions may be made:

2-1.1.1.1

In soft, cohesive soils, the point of fixity may be assumed to occur at a

depth of 3.05 m (10 ft.) below the mudline for piles having modulus of elasticity - moment

of inertia products (EI) of 2.925 x 10 kg-cm (10 x 10 lb-in ) or less. The point of fixity

may be assumed to occur at a depth of 3.66 m (12 ft) below the mudline for piles having

an EI greater than 2.925 x 109 kg-cm2 (10 x 109 lb-in2.) (E equals Modulus of Elasticity of

Pile in pounds per in and I equals moment of inertia of pile in in .)

2-1.1.1.2

In loose, granular soils and in medium cohesive soils, the point of fixity may

be assumed to occur at a depth of 2.44 m (8 ft) below the mudline for piles having an EI

of 2.925 x 109 kg-cm2 (10 x 109 lb-in2) or less, and at a depth of 3.05 m (10 ft) below the

mudline for piles having an EI greater than 2.925 x 109 kg-cm2 (10 x 10 lb-in .)

2-1.1.1.3

For other cases, assume a point of fixity at a depth of 1.5 m (5 ft) below the

mudline. The effective length factor K shall be taken as:

0.80 - when the deck structure is light, the piles have minimum embedment

into the pile cap and there is no special provision for moment transfer into

the deck structure.

0.73 - when the deck structure is light and provision is made for moment

transfer by embedment or other device into the deck structure.

0.65 - when the deck structure is heavy and a positive means for moment

transfer is provided.

NOTE: These provisions do not apply if pile embedment is less than 3.05

m (10 ft) into firm material or 6.10 m (20 ft) into soft or loose material. If lesser

penetration is achieved, assume that the pile tips are hinged. Also, the indicated effective

length factors (K) apply only if batter piles (minimum batter of one horizontal to three

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