Iranian Classification Society Rules

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Section 8 Pillars


801. General


1. Pillars in between decks are to be arranged directly above those under the deck, or effective means are to be provided for transmitting their loads to the supports belows.


2. Pillars are to be arranged below superstructures, deckhouses, windlasses and other heavy weights.


3. Doublers are to be allowed.


fitted on deck and inner bottom, except in tanks where doublers are not


802. Pillar scantlings

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The sectional area is not to be less than that obtained from the following formula :

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cm


supported load ( ), defined in Ch 2.

: defined in Table 3.3.17.

length (m ) of pillar.

:

radius of gyration (cm ), as following formula.


cm


: smallest moment of inertia (cm ).

: cross-sectional area (cm ) of


: correction factor for buckling, as following


and : static and dynamic load of


Table 3.3.17 Values of



0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3 and greater



0.057


0.063


0.069


0.076


0.084


0.094


0.105


0.119


0.136


0.158


0.113



803. Pillars in deep tanks


1. Hollow pillars are not accepted in deep tanks.


2. Where the hydrostatic pressure may give tensile stresses in the pillars and cross members, their sectional area is not to be less than that obtained from the following formula :


cm


: deck or side area (m ) supported by the pillar or cross member.

: design pressure (kN m ) giving tensile stress in the


804. Pillar bulkheads

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The transverse bulkheads supporting the longitudinal deck girders, and provided in lieu of pillars, are to be stiffened in a manner to provide than those required for pillars.


the longitudinal bulkheads supports not less effective

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