APB Group have extensive experience or working within tunnels and shafts carrying out repairs and refurbishment works
Mostly these projects have been carried out in closures or possessions and with a variety of additional constraints to overcome.
Our experience in tunnel and shafts dates to back more than thirty years right up until the present day.
APB tunnel and shafts expertise involves working with a variety of solutions in rail, highway and canal structures nationwide
APB are at the forefront of innovation in tunnel and shaft repair refurbishment and always striving to develop more productive solutions to increase outputs during possession and closures.
APB has a highly skilled in-house workforce and management team with many decades of experience between them working on highly complex and challenging tunnel and shaft repair projects, as well as working with industry leading specialist supply chain partners and professionals on more specialist tunnel and shaft repair projects.
In Watford Fast Tunnel APB carried out extensive repairs over and Easter blockade and mid week 6 hour ROR possessions. Works involved pressure pointing to brickwork, re-casing, pinning and grouting, resin injection to wet areas to replace lost mortar in a 4-ring brickwork tunnel, rock bolting and drainage repairs. In addition to stabilizing a very loose area in the crown caused by line mortar wash out, APB pin pointed the cause at the surface and developed with NWR a permanent solution. This involved installation of bulkheads to the rear of the lining, grouting of the cavity behind the lining and stage grouting the solution cavity in chalk feature above the crown.
At Bo Peep tunnel near Hastings, APB were engaged to carry out water sealing works to the roof of the tunnel and installation of new arch drainage working in possessions.
A large project to make safe unlined railway tunnels in North Wales was carried out by APB. This 12 week project mobilised at very short notice following some safety concerns. After scaling rock to remove loose sections, rock fall protection netting was installed and secured using pattern rock bolting. Modern coal mining rock bolting technology was used to drill the very hard rock with access being provided by a bespoke rail mounted platform based drilling and bolting rig arrangement which proved very successful. Blind shaft investigation works were also carried out as part of the project.
Monument Tunnel in Birmingham which carries an electrified line and OHLE required repairs involving surveying, rake out and pressure point brickwork, re-casing of ‘drummy’ areas, replacement of tablet markers and de-vegetation.
Similar repairs were also carried out at Shugborough Tunnel involving surveys, re-pointing and re-casing.
At Netherton Tunnel (one of the last canal tunnels to be driven) which was wide enough for passing narrow boats with tow paths to both sides, APB Group Ltd installed of a 25m length in the centre of this 2 mile tunnel: –
- ODEX drill and case piles with a ground beam to the foundation of both side walls
- Ram arch reinforced arch rig with sprayed concrete
- Re installed of tow paths
- Rock bolts to the area including approach sections
All using water borne pontoons and tugs and hopper access for material and waste. The Labour force used mountain bikes to speed up access and departure time.
At the Dudley Limestone Caverns APB Group installed rockfall protection netting and rock bolts to various “Cavern” areas to stabilize rock features and surfaces to maintain waterborne visitor access. All works were carried out from electric tug towed floating hoppers.
APB are able to offer a one stop shop to design and implement tunnel and shaft repair solutions using Standard Details where appropriate or developing bespoke solutions where required and can advise clients and asset owners about the most suitable approach to individual projects dependent upon constraints.
Most importantly when delivering civil engineering solutions in tunnel and shaft repair projects, an early contractor involvement and collaborative approach will always provide the client with the best engineering and most cost-effective solution.
