Greengate Street, "weak bridge" classification

I hope you can understand our concern in regard to the "weak bridge" classification of Greengate Street bridge, particularly as we are currently in the process of considering a proposed tenancy agreement from Netwrok Rail in regard to the four railway arches immediately below the area on Greengate Street bridge classified as a "weak bridge "
In paticular we would like to find out:

• What crieria is used to determine whether or not the structure is "weak"?
• What does "weak bridge" actually mean in terms of the structural integrity of the bridge.
• What, if any, impact would this have on the arches below the bridge, the bridge over the railway line and Marsh Street?
• Does this pose any possible risk, of any kind, to those using Greengate Street or living and working adjacent to the bridge?

We would be interested in hearing from all those responsible for the integrity and maintenance of structure and would like, if possible, to be provided with a copy of the complete structural survey that concluded and recommended this "weak bridge" classification and which may have possibly lead to the imposed weight restriction on vehicles.

Thank you in anticipation.