"Bruce" wrote in message
...

There are plenty of structures of this type (precast segmental
pre-stressed post-tensioned) but I think the Hammersmith flyover was
the first. I don't know of any subsequent structure of this type that
lacks the essential combination of bridge deck waterproofing, proper
drainage, adequate concrete cover to reinforcement/pre-stressing
tendons and grouting of tendon ducts.

So Hammersmith is very much a one-off. That doesn't mean that other
structures don't have problems of their own, but the design and
subsequent operation and maintenance practice related to the
Hammersmith flyover seems to have combined in a way that could only
end in tears.

I bet the DfT (or the Highways Agency) are glad that they they ceded all
the trunk roads within London to the GLA. I'm thinking it must have been
transferred at about the same time that all those random motorways within
London were downgraded?

Paul S