Civil Engineering Reference
In-Depth Information
Whilst the team may have developed some preconceptions
and preferences for the structural type during concept design,
it is at scheme design when different structural options will be
looked at and evaluated against one another. Concept design
should have defined the structural issues that need solving.
Scheme design will choose the systems that will be needed.
Detailed design will finalise the configuration of these systems
and deliver all the drawings, specifications and quantities that
will be needed by the contractor to construct the building.
Often events such as delays to receipt of information or deci-
sions or changes to previous assumptions will mean that some
aspects of these activities spill over into the next phase, but it
needs to be recognised by the team as a whole that this has the
potential for disruption, delay and cost each time it occurs.
If a building design team understands the client's brief,
studies the right options at concept design, agrees and records
decisions with the client and then develops, refines and con-
firms these at scheme design, it will be in a position to use the
detailed design stage to produce the final drawings and specifi-
cation almost without further input from the client. Early value
engineering can be used as part of this process to refine details
and optimise specifications, rather than lift the lid, late in the
day, on options that should have been properly considered in
the concept and scheme design stages, with the resultant dis-
ruption that flows from late change.
Pressures from the wider project will complicate this design
life-cycle, but by focusing on progress through these deci-
sions, with some appropriate flexibility, the structural team
will achieve a better result for all team members, and deliver a
better structure and building to the client.
team, so it is important that the structural engineer understands
and voices their opinion as opposed to focusing on the implica-
tions of the architect's view.
Sometimes there are direct client instructions and a clear
brief, but often the client's needs and aspirations for the project
emerge during meetings and correspondence during the earliest
project stages - the client's own view of the project will often
be evolving at the same time as that of the team. This is one
of the reasons why the structural engineer should be proactive
around the project table as early in the design process as pos-
sible, allowing a first-hand understanding of developing client
thoughts. As the brief develops, the engineer should 'reflect it
back' in writing to the wider project team to make sure there is
a shared direction.
During these early project stages and throughout the pro-
ject it is worthwhile for the structural engineer to remind
themselves that they are the structural expert and therefore
should lead the structure's development. Often the client
and other team members will believe that they fully under-
stand the subject - all humans deal with gravity on a daily
basis and believe they have an appreciation of what steel and
concrete are. Many project managers come from a structural
background and architects love to play with structural forms.
They all probably think they know the answers.
They may know some of them, but most likely not all. A
proactive engineer will build on this basic understanding with
enthusiasm as we all like subjects we think we understand, and
will engage with the team regarding the structural issues faced.
A structural engineer as team teacher can promote a fully inte-
grated approach across the wider project and this will lead to a
better final building.
A subject that is likely not to be explicit in the client's brief
is the external constraints posed by the site. The strength and
stiffness of foundations, external sources of vibration, buried
services or archaeology, road and rail limitations, adjacent
slopes and construction access are among the constraints that
need to be understood by the whole design team as solutions
are investigated. The structural engineer is the natural leader in
these subject areas and may need to define the investigations
and decision processes required.
Where multi-disciplinary design teams are working beyond
their previous experience, in a new geography or on a building
type they have not previously constructed, the engineer should
also play a role as the brief's structural interpreter to the team.
In areas with high winds, severe corrosion and, in particular,
earthquakes, the final structure will impose greater constraints
on the multi-disciplinary building form and an understanding
of the structural needs across the team will greatly reduce frus-
trations, problems and rework later in the design process.
7.2.2 Understanding and anticipating the brief
Clients wanting a multi-storey building do not actually want a
structure. Their priority is the functions they want to carry out
inside the building. If someone invented an anti-gravity machine
that could effectively and cheaply keep carpets apart the struc-
tural engineer would be out of a job! Given that the structural
engineer's role is to provide a currently necessary evil it is there-
fore important that they properly understand what the client
actually wants so that the structure does not compromise these
aims and literally and metaphorically supports them.
Often the engineer will focus on the structural implications of
the architect's design. However, it should not be forgotten that
this is already one step removed from what the client actually
asked for - it is the brief viewed through the architect's eyes.
The structural team needs to have its own clear understand-
ing of:
What does the client say they need?
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Do they have any particular priorities?
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7.2.3 The brief's impact on the structural form
Several aspects of the brief and the concepts developed by the
team in response, either explicitly or implicitly expressed, will
have particular impact on the final structural form.
Do they have needs not stated?
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The list of implications that jump out of the brief can be differ-
ent when read by the different members of the multi-disciplinary
