I find a
conference a great way to rapidly take the temperature of a subject, and since
I am increasingly discussing the future of bridges attendance at the ICE's
Bridge Conference 2014 seemed a useful chance to plug into the state of the art.
According
to Mike Chrimes, chairing the day, the three key subjects would be
Design for Manufacture and Assembly (DfMA), Digital Engineering and Asset
Management. These are where it’s all happening for bridges at the moment but I
found there were lots of the last, some of the first and surprisingly little
BIM. Let me highlight some of the key moments:
Roger Ridsill Smith of
Foster and Partners discussed "inevitable design" - not imposing
solutions that fly in the face of 'the right path', having the courage to
do the obvious. His key example argued that the right place for the Millennium Bridge
had to be at the foot of St Paul's steps to connect to the City - not on
axis with the Tate as many wanted. He also showed a great graph
summarising research revealing a
straight line relationship between the embodied energy of a
material and its cost. His message was this requires you to minimise
material usage, whatever the project type is. I liked that message.
As always
Roger was thought provoking, with ideas that other speakers returned to. However,
despite agreeing, part of me wanted to debate the flip side of the same coin -
where the right path is the one which no one else is prepared to take.
Steve Nicholson, Chief
Executive of Mersey Gateway gave a summary of the five years it has taken
to reach financial closure and how the relatively small Borough of Halton
is dealing with building this major transport link. Reduction of CAPEX
over the next 30 years has been the key. Construction is planned to occur
from deck level, driven by the large tidal range beneath, with insitu
pours and some very clever movable, collapsible formwork.
Mariapia Angelino of Bristol
University looked at the next phase of developments in the Eurocodes for
Bridge Design. Ease of use will be a key driver of change, as many of
these codes are tough to use at the moment. The opportunity to influence
the new versions is now!
Keith Ross of Network Rail
discussed a subject I had never looked at before: Bridge strikes and more
specifically the interface of roads with rail bridges. The number of
times some bridges get hit per year is amazing! One bridge in Tulse Hill
was hit 21 times in 2013! Also what is going on in Grantham!!!There is
an amazing amount of disruption and work tied up around this issue and really
shows the importance of planning the future life of an asset. Guidance on
the prevention of strikes on bridges over highways will be available on
a www.gov.uk bridge strike page and all bodies involved are supporting the
initiatives.
The next two presentations
felt like a connected pair. Fernando Osan Sarasa, who I met quite
recently, talked about some beautiful work he has done in Spain designing
precast continuous bridges. For one example the bridge decks was finished
only six and a half weeks after the climbing formwork of the tall piers
was complete and the bridge was in service three weeks after that!
Thomas
Garcia, the lead bridge engineer for HS2 then spoke of their key aim to develop
families of structures that maximise off site solutions - music to my ears. HS2
has 135 over bridges (taking things over the railway), 185 under bridges and 70
viaducts totalling 30km, so the need for a solution is clear. Laing O’Rourke’s
approach at Leadenhall was highlighted as the example of the DfMA behaviours
needed.
HS2 has
developed a BIM model of a 50km section of the alignment and the plan will be
to link models and information into the final asset management system as a key
deliverable. Building up BIM related skills across the whole team is needed. As
soon as someone says 'Just print off the PDFs and I'll mark it up' the process
begins to break down. They plan to investigate links to gaming technology as a
way to keep people 'inside BIM.'
The
intention is to go out for tender in a few weeks to find a consultant to
develop these families. A key part of that work will be to develop
specifications driving a reduction in the inspection and maintenance required.
During questions a member of the HS1 maintenance team observed that they can't
use standard inspection access equipment on apparently similar bridges.
Standardisation of maintenance and inspection will also need to be solved.
Barry Colford, Bridgemaster
at the Forth Road Bridge gave a fascinating overview of the last 50 years
that really brought home the need to consider asset management. Fun fact
of the day was that the bridge cost £11.5 million to build and has cost
£250 million to maintain. Wow! We later learned that when it gets
repainted in 2016 there are 200,000m2 to paint, and of the £350 per square
metre, only £7 is for the paint - think about that as you design!!
Paul Monaghan from the City
of London and also LoBEG (London Bridges Engineering Group) gave an
excellent overview of the ways they are improving the management if their
assets. Their approach is based around four key areas: data and
information, systems and processes, decision support tools and procedures
and finally training and continual improvement.
I was
impressed by what he showed of the Bridgestation mobile web-based system.
Contractors will need to engage with this developing language and software as
fulfilling the client's needs via information and processes is of increasing
importance. Designers also need to think about maintenance right up front! It
takes up to 8 people to change light bulb on the Millennium Bridge (no joke),
so single failures are left until they are dealt with in a batch. The design
had required site drilled holes, but the owners only discovered that after they
had taken off all the covers and got them mixed up. It took 4 months to get
them sorted and back on. Finally, what is a client to do when contractors and
consultants say a bearing has a life of 30 to 50 years? What is the test they
must apply to decide replacement is needed?
Bill Harvey made a poetic point
that we bring energy together in a bridge and from that point we need to
invest energy in order to stop it leaking away.
Wrapping up, Cam Middleton,
the Laing O'Rourke Professor of Construction Engineering talked about the
technologies that are shaping the future of bridge engineering. The key
was standardisation and off site manufacture: the legoisation of bridge
construction. American examples of Accelerated Bridge Construction (ABC)
were discussed and I must find the US government web sites he mentioned.
For new build the aim is "get in, get out, and then stay
out". Key aspects for the future include digital asset information
modelling, smart sensors and monitoring, advanced analysis and the use of
new materials.
He
finished with a great idea: " Systemicise new-build so the best
minds can work on refurbishing the old assets." Simplify the new so we can
all focus on saving the old. That takes some thinking about for our industry!
