Civil Engineering Reference
In-Depth Information
quality plan and the requirements during construction until commissioning and
start-up.
In considering the construction philosophy and contract strategy, the objec-
tives of achieving quality requirements and efficiency are of fundamental
importance.
Construction of the offshore structure jacket goes through a series of very
distinct stages from the start of fabrication until the load-out. The stages
begin with obtaining the steel sections, which are delivered from the manufac-
turer. The intiation of fabrication in some stages will be manual, with less
quality control. Thus, efficiency decreases as progress is made through the
operations. A third basic consideration is that risk increases with each progres-
sive stage.
It is clear, therefore, that, as a general principle, as much work as possible
should be undertaken in the earlier, more productive, higher-quality, less risky
phases of the project.
Some of the principles that reduce the time and cost of construction are:
Subdivision into as large components and modules as it is possible to fab-
ricate and assemble.
●
The fabrication of major components in the best location and under the best
conditions applicable to each component.
●
Delivery of critical materials by early planning of the flow of components to
their assembly site.
●
Providing adequate facilities and equipment for assembly, including such
items as synchrolifts and heavy-lift cranes.
●
Simplification of the configurations and standardization of details, grades
and sizes. Avoidance of excessively tight tolerances.
●
In general, structural systems should be selected that utilize skills and trades on
a relatively continuous and uniform basis. Procedures that are overly sensitive
to weather conditions should be avoided; processes that are weather-sensitive
should be completed during shop fabrication (for example, application of the
protective coating).
●
The quality-management system is a vital and integral component of all
aspects of offshore fabrication because small mistakes can affect the integrity
of the structure over time. Essentially, quality management involves ensuring
that what is produced is what is needed. The requirements for documentation,
hold point, audits, reviews and corrective actions are part of the quality-assurance
process. They are crucial tools for controlling the project
'
s execution and for
providing verifiable evidence of the fabricator
s competence.
Quality control, inspection and testing should be performed during all phases
of construction to ensure that specified requirements are being met. The most
effective quality scheme prevents the introduction of defective materials and
workmanship into a structure, rather than finding problems after they occur.
'
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