ISO 19903:2019 石油および天然ガス産業—コンクリートのオフショア構造 | ページ 6

3.1

abnormal design situation

design situation in which conditions exceed conventionally specified design conditions and which is used to mitigate against very remote events

Note 1 to entry: Abnormal design situations are used to provide robustness against events with a probability of typically 10⁻⁴ per annum or lower by avoiding, for example, gross overloading.

3.2

abnormal level earthquake

ALE

intense earthquake of abnormal severity under the action of which the structure (3.51) should not suffer complete loss of integrity

Note 1 to entry: The ALE event is comparable to the abnormal event in the design of structures which are described in ISO 19901-2 and ISO 19902. When exposed to the ALE, a manned structure is supposed to maintain structural and/or floatation integrity for a sufficient period of time to enable evacuation to take place.

3.3

accidental design situation

design situation involving exceptional conditions of the structure (3.51) or its exposure

3.4

action

external load applied to the structure (3.51) (direct action) or an imposed deformation or acceleration (indirect action)

[SOURCE:ISO 19900:2019, 3.3]

3.5

action effect

result of actions (3.4) on structural components or on the structure

[SOURCE:ISO 19900:2019, 3.4]

3.6

addition

finely divided material used in concrete (3.12) in order to improve certain properties or to achieve special properties

3.7

admixture

material added during the mixing process of concrete (3.12) in small quantities related to the mass of cement to modify the properties of fresh or hardened concrete

3.8

aggregate

granular mineral material suitable for use in concrete (3.12)

Note 1 to entry: Aggregate can be natural, artificial or recycled from material previously used in construction.

3.9

air cushion

air pumped into underbase compartments of the structure (3.51)

Note 1 to entry: The air cushion is normally applied in order to reduce the draft and increase the freeboard of the structure and/or to alter the structural loading.

3.10

atmospheric zone

part of the load-bearing structure (3.51) that is above the splash zone (3.50)

3.11

caisson

major portion of concrete (3.12) offshore structure (3.51) , providing buoyancy whilst afloat and the possibility of oil storage within the structure

Note 1 to entry: The caisson is generally divided into watertight compartments, which can be subdivided into intercommunicating cells for structural reasons. The caisson can also be filled, or partly filled, with ballast water and solid ballast (3.49) .

3.12

concrete

material formed by mixing cement, coarse and fine aggregate (3.8) and water, with or without the incorporation of admixtures (3.7) and additions (3.6) , which develops its properties by hydration of the cement

3.13

condition monitoring

evaluation of the condition and behaviour of the load-bearing structure(s) (3.51) in service using data from design, inspection (3.29) and instrumentation (3.31)

3.14

construction afloat

fabrication, construction and related activities taking place on a structure (3.51) that is afloat, normally at an inshore location and restrained by a temporary mooring system

3.15

deck mating

marine operation (3.35) in which the platform topsides (3.55) is floated into position and connected to the substructure

Note 1 to entry: This operation is normally conducted by ballasting and deballasting of the substructure.

3.16

deep water construction site

site for construction of the structure (3.51) while afloat

Note 1 to entry: The use of a deep water site might not always be required, depending on the construction method. It might or might not be the same location as that where mating of topsides (3.55) to the substructure takes place.

3.17

design rule

rule in accordance with the chosen reference standard for concrete (3.12) design

Note 1 to entry: See 8.2.

3.18

design wave

deterministic wave used for the design of an offshore structure (3.51)

Note 2 to entry: Normally, a design wave is only compatible with design situations in which the action effect(s) are quasi-statically related to the associated wave action on the structure.

[SOURCE:ISO 19901‑1:2015, 3.5]

3.19

dynamic amplification factor

ratio of a dynamic action (3.4) effect to the corresponding static action effect (3.5)

Note 1 to entry: An appropriately selected dynamic amplification factor can be applied to static actions to simulate the effects of dynamic actions.

3.20

extreme level earthquake

ELE

earthquake with a severity which the structure (3.51) should sustain without major damage

Note 1 to entry: The ELE event is comparable to the extreme environmental event in the design of structures which are described in ISO 19901-2 and ISO 19902. When exposed to an ELE, a structure is supposed to retain its full capacity for all subsequent conditions.

3.21

execution

activities carried out for the physical completion of the works (3.55) , including procurement, inspection (3.29) and documentation thereof

Note 1 to entry: The term covers work on site; it might also signify the fabrication of components off-site and their subsequent erection on site.

3.22

exposure level

classification system used to establish relevant criteria for a structure (3.51) based on consideration of life-safety and of environmental and economic consequences of failure

Note 1 to entry: The method for determining exposure levels is described in ISO 19900. An exposure level 1 platform is the most critical and an exposure level 3 the least. A normally manned platform that cannot be reliably evacuated before a design event will be an exposure level 1 platform.

[SOURCE:ISO 19900:2019, 3.20, modified — “consideration of life-safety and of environmental and economic” has been added to the definitions and the Note 1 to entry has been added.]

3.23

finite element analysis

analysis method whereby a structure (3.51) or a part thereof is subdivided into small elements of known or assumed behaviour, then analyzed by numerical matrix methods to determine action (3.4) effects, static or dynamic

3.24

fixed concrete offshore structure

concrete (3.12) structure (3.51) designed to rest on the sea floor

Note 1 to entry: Sufficient structural stability can be achieved through its own weight, or in combination with suction in skirt compartments, or founding of the structure on piles into the seabed. It includes the mechanical outfitting of the structure.

3.25

fixed structure

structure (3.51) that is bottom founded and transfers most actions (3.4) on it to the seabed

[SOURCE:ISO 19900:2019, 3.24, modified —"all" has been changed to"most".]

3.26

floating concrete offshore structure

concrete structure (3.51) where the full weight is supported by buoyancy

3.27

float-out

transfer of a major assembly from a dry construction site to a self-floating condition

Note 1 to entry: Typically, it is the transfer of the lower part of the concrete (3.12) structure (3.51) from a flooded drydock.

3.28

global analysis

determination of a consistent set of either internal forces and moments or of stresses for a complete structure (3.51) usually resulting from the finite element analysis (3.23) .

3.29

inspection

conformity evaluation by observation and judgement accompanied, as appropriate, by measurement, testing or gauging to verify that the execution (3.21) is in accordance with the project work specification (3.44)

3.30

installation

marine operation (3.35) in which the platform is positioned and set down on the sea floor at the offshore site (3.38)

3.31

instrumentation

outfitting of a concrete (3.12) offshore structure (3.51) with instruments for data measurement and recording

3.32

interface manual

document defining all interfaces between the various parties and disciplines involved in the design and construction, ensuring that responsibilities, reporting and information routines, as appropriate, are established and maintained

3.33

lightweight aggregate

aggregate (3.8) of mineral origin having an oven-dry particle density 2 000 kg/m³ or a loose oven-dry bulk density 1 200 kg/m³

3.34

local analysis

determination of a consistent set of internal forces and moments, or stresses, in a cross-section of a structural component, or in a subset of structural components forming part of the structural system, that are in equilibrium with the boundary conditions

3.35

marine operation

planned and controlled vertical or horizontal movement of a structure (3.51) or component thereof over, in or on water

3.36

method statement

document stating the methods and procedures (3.42) used to perform the work (3.56)

3.37

normal-weight aggregate

aggregate (3.8) with an oven-dry particle density between 2 000 kg/m³ and 3 000 kg/m³

3.38

offshore site

offshore location where the structure (3.51) is installed for its operational life

3.39

operations manual

document giving the requirements and restrictions related to a safe operation of the concrete (3.12) structure (3.51) and all its systems

3.40

owner

representative of the companies which own a development

Note 1 to entry: The owner will normally be the operator on behalf of co-licensees.

3.41

primary structure

all main structural components [ concrete (3.12) or steelwork] that provide the structure’s (3.51) main strength and stiffness

3.42

procedure

document that describes a specified way to carry out an activity or a process, the detailed sequence and interrelationships required for the completion of a particular task

3.43

project specification

document giving the overall technical requirements provided by the owner (3.40)

3.44

project work specification

information and technical requirements necessary for the execution (3.21) of the works (3.56) , including documents and drawings, etc., as well as references to relevant regulations, specifications, etc.

3.45

quality plan

document specifying the procedures (3.42) and associated resources to be applied, and by whom and when, covering the entire project or defined parts of the project and all relevant products, processes or contracts

3.46

secondary structure

structural components that do not contribute significantly to the overall strength and stiffness of the structure (3.51) but which support individual items of equipment, transferring the actions (3.4) thereon onto the primary structure (3.41)

3.47

shaft

compartment extending from the caisson (3.11) of the concrete (3.12) offshore structure (3.51) to the topsides (3.55)

Note 1 to entry: A shaft is generally used to house and support the wells (drill shaft), mechanical systems (utility shaft) and risers and J-tubes (riser shaft). The part of a shaft extending above a caisson is also often referred to as a leg.

3.48

skirt

structural component constructed in concrete (3.12) and/or steel that is part of the foundation and penetrates into the seabed

Note 1 to entry: Skirts are used to increase the capacity of the foundation to resist vertical and horizontal actions (3.4) and improve erosion resistance. Skirts can also be needed to form compartments facilitating the under-base grouting.

3.49

solid ballast

non-structural material added to a structure (3.51)

Note 1 to entry: Solid ballast is normally applied in order to increase the self-weight of the structure or to lower the centre of gravity for floating stability purposes.

3.50

splash zone

area of a structure (3.51) that is frequently wetted due to waves and tidal variations

3.51

structure

combination of physically connected structural components designed to withstand actions (3.4) and provide adequate rigidity

[SOURCE:ISO 19900:2019, 3.53, modified — added text from"designed".]

3.52

submerged zone

part of the structure (3.51) that is normally submerged and exposed to the constant influence of sea water

3.53

subsidence

part of the settlement of the structure (3.51) that results from extraction of reservoir hydrocarbons and factors other than the weight of the structure

3.54

summary report

document including the most important assumptions on which the design, construction and installation (3.30) work is based with regard to the load-bearing structure (3.51)

3.55

topsides

structure (3.51) and equipment placed on a supporting structure (3.51) (fixed (3.25) or floating (3.26)) to provide some or all of a platform’s functions

Note 1 to entry: A separate fabricated deck or module support frame is part of the topsides.

[SOURCE:ISO 19900:2019, 3.54, modified — Notes 1 and 2 to entry have been omitted.]

3.56

works

construction work described in the project work specification (3.44)

3.57

works certificate

mill certificate

Note 1 to entry: A works certificate is normally required for construction materials that are not subject to an accepted certification scheme.