Diolkos - Structural design

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Structural design

What work items should be included in a structural design of a building project?
In general, should be included:
- Working with the architectural firm for the shaping of architectural form in plan and elevation. Apart from the provision of the structural system of the building, so as to be architecturally acceptable, compliance is required in order to be functional in seismic actions. Greece is a seismic area and the regularity of the building is a requirement of seismic standards (EN-1998).
- Final configuration of the structural system of the building and an update send to the architect.
- Preparation of the required calculations which will confirm the dimensions of the structural system and will identify the location and amount of reinforcement.
- Any modification of the structural drawings and the final update to the architectural firm.
- The design of reinforcement drawings, details, cut and shaping of rebars.
- The bill of quantities for the materials separated at every construction phase.
- The presentation of the design.
- Support of the design to the public administration, if required.
- Support to the client in order to select / inform the construction team of the structural system
Are all structural designs comparable so that the cost of the design to be the main selection criterion for the designer?

Conditions for a good design (for whatever this means), is the experience, in depth examination and the personal engagement with it. From this alone it is evident that "cheap" designs can hardly be good.
Can the structural software be a criterion for the quality of the design?
It is necessary condition but not a sufficient. The reason is that there is a precondition for almost all designs of complex calculations, which assume software reliability. A key point is that, nowadays, are many "automatic" programs, where a possible graphic description of the project produce calculations and drawings. But in this way:
- The relation of engineer to the project is reduced, so the risk of errors and misunderstandings about the capabilities of the program is increased. Continued use of programs in this way, reduce also the possibility of acquiring experience by the engineer, beyond that of using a specific program.
- It is not possible to optimize the project (in programs you get what you give).
- Many of these programs are developed by engineers and analysts with reduced experience in structural designs (since they do not perform this activity).
For some reason I had a structural design that does not satisfy me. Is it worthwhile to pay for a new?

Although the design may have problems (technical, cost) it's no doubt, as long as the new one will not incorporate the same problems.
What is the relationship between an architect with a (structural) engineer?

Practically no more than the fact that, at least in building projects, belongs to the same production chain (but in a different link). The architects are the key engineers from whom an individual should begin, all others work (structural engineer, electrical engineer) is depended on that of the architect but they must be chosen at the beginning of the project (before completion of the architectural design), so to properly assist the architect.
Other engineers to select by the architect?

All other engineers are doing a job which, although more technical, also referred to the owner. This choice is based on experience (hence the projects he has involved, and how), professionalism and human relationship.
Is it worth to pay money for designs?

Designs are prepared by professionals who are sometimes proper and sometimes not. A proper one does not accept to make "cheap" design, though doesn't mean that expensive = proper.
Basic rule: The construction, at best, will become as good as designs allows.
Do I need a geotechnical survey for my project?
As a principle is needed. The geotechnical survey creates conditions for increased security the project and the related investment. But there are criteria on the basis of which may be waived. Examples such could be:
- The size and scope of the project.
- The knowledge of local soil conditions in connection with the project.
- The existence of such investigations in the vicinity of the project that their evaluation can provide information on the project.
- The seismicity of the region etc.
An outline of the conditions given by the current standards (Greek Earthquake resistant code) and those implemented in the near future (EN 1990). But there are always under judgment for the specific case and ultimately the decision to perform or not such research has economic criteria alone and do not contribute to any other advantage. Contrariwise failure caused by the foundation soil, almost always, draws great consequences.
Who then decides whether and to what extent geotechnical investigations should be performed?

Initially the structural engineer. He will determine if the size of the project, according to the information for the foundation soil of the region, requires such.
It is also the one who, during the excavation for the foundation of the project, will evaluate (either alone or with the help of geotechnical engineer) if the assumptions made were reasonable (or almost because the evaluation is visual and for the soil above the foundation level) or possibly execute locally a deeper trench or require a full investigation.
But it is very likely during the preparation of structural design (if so decided) to require geotechnical investigation. This will need a geotechnical engineer.
This engineer based on information received from the region, the extent of work and other information that the structural engineer will provide, will prepare a research program that once executed, will evaluate in the form of directives, numeric parameters or by other means in order to be applied to the structural design of the project or project area.