Paisley Gilmour Street Railway Station Canopy Renewal Canopy ...

Paisley Gilmour Street Railway Station Canopy Renewal
5. Details of proposal design and materials.
5.1. Glazing.
The roof glazing system consists of 6.4mm laminated planar glass supported
and restrained by PL6 glazing bars and supported by steel purlins which span
between new steel pitched roof beams.
5.2. Foundations and substructure.
It is anticipated that existing column foundations which are supported on fill
between the retaining walls of the original station will require strengthening.
The form of strengthening is envisaged to be enlargement of the existing pad
foundations using dowels and reinforced concrete to reduce bearing
pressures on the substructures.
5.3. Superstructure.
The existing lattice girders will be strengthened using the following
techniques:
Additional flange plates will be bolted to the soffit of the main lattice girders
in order to enhance the bending capacity of the girders.
The main lattice girder web members will be strengthened by the addition
of angles or channels to the end members in order to carry the shear
forces from the end of the beam down to the supports.
The main strengthening works involve the addition of a rolled steel beam
section above the main lattice girders in order to significantly increase the
section depth. The beam will be bolted at approximately 150mm centres to
the top flange of the girder in order to provide a longitudinal shear
connection. The soffit of the proposed rolled steel section will be notched
over the locations where the OHLE supports are positioned above the top
flange of the lattice girders.
The rolled steel beams will act as valley girders and will accept the main
pitched roof beam sections. The roof beams will be tied in order to limit
lateral loading effects on the existing lattices during construction.
The existing columns have been found to be inadequate to resist wind
loading effects and therefore horizontal plan bracing will be introduced in
the end bays in order to carry the loads back to the main masonry
supporting walls. These loads will be distributed along the length of the
wall by longitudinal beams positioned just in front of the masonry walls.
Additional longitudinal beams will be included along platform 2/3 above the
existing bow tie members in order the distribute loads down the length of
the station.
The roof is joined to the wall of the building with lead capping to the
cornice and blocking course to parapet. This is detailed in drawing
A057311-31-A-301.
Laura Mitchell for NETWORK RAIL Page 4 of 6