// CODE SNIPPET
3107F.3.3.2 Displacement Capacity
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(7-35)
FIGURE 31F-7-15
ASSUMED IN-GROUND FIXITY
(7-36)
(7-37)
(7-38)
(7-39)
A distinction shall be made between a pier-type pile, with a long unsupported length and a wharf-landside-type pile with a short unsupported length between the deck and soil. The effective length, L, is the distance between the pinned deck/pile connection and in-ground fixity as shown in Figure 31F-7-15. For pier-type (long unsupported length) vertical piles, three simplified procedures to determine fixity or displacement capacity are described in UFC 4-151-10 [7.12], UFC 3-220-01A [7.13] and Chai [7.14].
In order to determine fixity in soft soils, another alternative is to use Table 31F-7-8.
The displacement capacity, Δ, for a pile pinned at the top, with effective length, L, (see Table 31F-7-8 and UFC 4-151-10 [7.12]), and moment, M, is:
(7-35)where:
| E | = | Modulus of elasticity |
| I | = | Moment of inertia |
ASSUMED IN-GROUND FIXITY
| PILE EIg | SOFT CLAYS | LOOSE GRANULAR & MEDIUM CLAYS |
| < 1010 lb in2 | 10 feet | 8 feet |
| > 1010 lb in2 | 12 feet | 10 feet |
Assuming linear curvature distribution along the pile, the allowable curvature, ϕa, can be established fromml:
(7-36)where:
εa = allowable strain limit according to Section 3107F.3.3.3
c = distance to neutral axis which can be taken as Dp/2, where Dp is the diameter of the pile
The curvature is defined as:
(7-37)The maximum allowable moment therefore becomes:
(7-38)The displacement capacity is therefore given by:
(7-39)Related Code Sections
3107F.3.3.2 [SLC] Marine Oil Terminals, Displacement Capacity
-7-15. For pier-type (long unsupported length) vertical piles, three simplified procedures to determine fixity or displacement capacity are described ...
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The displacement demand and capacity of existing timber
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California Building Code 2019 (Vol 1 & 2) > 31F [SLC] Marine Oil Terminals > 3107F Structural Analysis and Design of Components > 3107F.3 Timber Piles and Deck Components > 3107F.3.2 Deformation Capacity of Flexural Members
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To assess displacement capacity, two-dimensional
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California Building Code 2019 (Vol 1 & 2) > 31F [SLC] Marine Oil Terminals > 3104F Seismic Analysis and Structural Performance > 3104F.2 Existing MOTs > 3104F.2.3 Analytical Procedures > 3104F.2.3.1 Nonlinear Static Capacity Procedure (Pushover)
3104F.2.3.1 [SLC] Marine Oil Terminals, Nonlinear Static Capacity Procedure (Push-Over)
To assess displacement capacity, two-dimensional nonlinear static (pushover) analyses shall be performed; three-dimensional analyses are optional. A ...
California Building Code 2016 (Vol 1 & 2) > 31F [SLC] Marine Oil Terminals > 3104F Seismic Analysis and Structural Performance > 3104F.2 Existing MOTs > 3104F.2.3 Analytical Procedures > 3104F.2.3.1 Nonlinear Static Capacity Procedure (Push-Over)