St Ninians Pedestrian Footbridge

LocationSt Ninians, Stirling
RequirementBearing piles to support new footbridge
Techniques
Main ContractorStory Contracting

Project Overview

Piled foundation were required to support a new Network Rail pedestrian bridge which was being constructed to replace an old level crossing on the main Stirling to Edinburgh Line.

Ground conditions in this part of Scotland are notoriously weak to significant depths.

Project Challenges

  • Working adjacent to live running line.
  • Vibration restrictions, due to proximity of the rail infrastructure.
  • Preliminary pile testing.

Solution Delivered

The works involved installing 84 No. low vibration bottom driven piles to a depth of up to 20m adjacent to the live running line.

Compression and tension loads were 350kN and 125kN respectively. Work was carried out very close to the live railway, so TGS’ short mast rigs were used. Full depth pile reinforcement was also installed in sections no greater than 3m to conform to the live rail fall distance restrictions. Multiple rigs were used to complete the work in the required programme.

Preliminary testing was also carried out to ensure appropriate pile capacities were achievable within the notoriously weak ground conditions present.