A9 Dualling: Luncarty to Pass of Birnam - Construction update - Summer 2019
The earthworks stage of the project continued throughout Summer 2019 with the majority of earthworks to the south of the new Stanley/Tullybelton junction nearing completion.
North of the Stanley/Tullybelton junction, earthworks continued with the excavated material from Bankfoot being used as fill material for the construction of the Tullybelton East junction. The earthworks around this structure included the shaping of the approach embankments on either side of the junction which will form the new slip roads to tie into the existing Stanley road. In total, approximately 610,000 m3 of material had been excavated by the end of August 2019, enough to fill 244 Olympic size swimming pools.
The traffic management for the site underwent a change in June 2019 as a temporary mini-roundabout was installed south of Bankfoot. The temporary mini-roundabout helps to manage the safe flow of traffic during construction of the new A9 dual carriageway.
The temporary roundabout allows site vehicles direct access from the A9 to the quarry located at Loak Farm which provides the materials essential for the construction of the project and reduces the volume of construction vehicles on the local road network, which would otherwise need to come from quarries further afield.
Carriageway drainage on the southern end of the project commenced in July which involved laying pipes along the length of the new carriageway. Drainage is a key part of any road network as it allows surface water to run off the new carriageway to designated collection basins, ensuring the safe operation of the road for road users.
Works continued at Shochie and Ordie Burns to extend these culverts to allow for the wider A9 dual carriageway.
The project reached a significant milestone at the end of July following three overnight closures of the A9 to allow the installation of bridge beams to construct the new Stanley/Tullybelton junction. A total of 15 beams weighing 765 tonnes - the equivalent of 60 double decker buses – were installed to form the new structure over the carriageway. During the month of August, work began on the construction of the deck of this structure.
Construction of the concrete columns at Pitlandie, Coltrannie and Gelly overbridges progressed during August.
At Bankfoot North Junction, works to extend Hunters Lodge underpass progressed with the southern abutment cast.
The steep embankment at Broompark was cut to make way for the new dual carriageway. Soil nails were used to stabilise the steepened slope. Soil nailing involves drilling holes into the slope and fixing long steel bars into the holes with grout.
Further north of Bankfoot, site clearance and boundary fencing works continued, with earthworks commencing in the area to prepare for the construction of the two new overbridges at Coltrannie and Gelly.
The traffic management to the south of Luncarty junction was altered at the end of August to allow the first 2.4km of new carriageway to be constructed and tied into the existing dual carriageway. In advance of the new carriageway being constructed, drainage and foundation layers for the road were completed in preparation for the Cement Bound Granular Material (CBGM) being laid on this stretch.
The CBGM material is produced at the onsite batching plant adjacent to the project office at Loak Farm, along with some of the raw materials for the concrete and road pavement.