project: Wyke Tunnel Concrete Repairs

client: Weymouth & Portland Borough Council
location:
 Weymouth
duration: 2 months
value: £150,000

scope of works:

New drainage channels and soakaways
Water jet preparation
Fix permanent drainage layer to membrane
Installation of reinforcement mesh
Sprayed concrete 

The works were carried out from May to July 2013. The scope of works included preparation of the tunnels existing brick surface using high pressure water jetting and the application of a new Delta drainage membrane; comprising the Delta 500 membrane secured to the brick surface using delta quick seal plug fixings and dressed into the stone quoins at either end of the tunnel. The membrane was then covered by a sprayed concrete lining reinforced with a steel mesh, fixed with steel dowels to the original brick structure.

To allow for drainage a 100mm plastic pipe was set into the tunnel lining with weep holes at 1.5m centres, this then feeds into the new ACO drainage channel formed within the concrete foundation of the tunnel lining. The drainage channel leads to Soakaways at the North end of the tunnel, comprising of a perforated down pipe in 10mm pea shingle fill encased with Geotextile to top and sides.

Access was achieved with the use of a fixed platform scaffold during preparation works and mobile scaffold platforms for the remainder of the works. Heras fencing and diversion notices were used to close off the Rodwell Trail path during the project.