Bachy Soletanche holds back the Waterfront for a Carlow project in Ireland

Leading geotechnical specialist, Bachy Soletanche Limited (BSL) has completed piling work for a €15million Waterfront office development at the heart of Carlow – one of Ireland’s fastest growing towns. The project involved the construction of a bored pile secant wall; one of the first in the locality whilst programming work around a simultaneous re-routing of the sewer system took place. The sewer line was located directly underneath the site and although piling would not usually begin until the sewer had been re-routed, careful and innovative project programming meant that both projects could continue simultaneously.
Ged Neary, general manager for Ireland at Bachy Soletanche explained:
“We were approached by our client, Quinn Reddin Limited (QRL), a Carlow based development and building contracting company, to provide piling works for the construction of a secant wall design on their development – but as we neared completion of the piling guide wall, the diversion and removal of the main sewer line, running directly through the project site had not been completed due to unconnected factors. This meant the sewer line had to be re-directed whilst piling progressed in limited unaffected accessible areas, in order to prevent project delays which could have extended to several weeks.”
“Due to the tight completion deadlines, BSL & QRL developed a programme to work around the sewer diversion works. This allowed the piling element of the project to be completed only a couple of days behind the original schedule, rather than delay the project for a month or so as initially envisaged.” He added.
The site for the office development is in a very scenic location, nestled between the River Barrow and the remains of Carlow Castle. Only fifty miles away from Dublin, Carlow has become a popular commuter hotspot; and the attractive town is now encouraging businesses into the area with the construction of the soon-to-be-completed Waterfront offices.
The secant wall installed by BSL provides the core framework for the construction of an underground parking facility that was integral to the overall project. Ged Neary commented:
“The original design incorporated a low single storey basement but the design was later adjusted to increase the basement depth. As BSL’s in-house design team had provided the original pile design, adjustments were able to be made relatively quickly and easily, with no real impact on the construction programme.”
“Once the final amendments were approved, the piling work for the secant wall could then begin.” He added.
In a contract valued at around €350,000, BSL used the Continuous Flight Auger (CFA) piling method to construct the hard/firm secant wall within an eight-week schedule. A BG-18, high torque CFA rig was used to construct 426 CFA piles, each with a 600mm diameter. The piles were bored to a depth range of 7-9 metres, providing the core structure for the basement walls whilst cutting off groundwater ingress into the basement excavation.
Ged Neary added:
“Although we faced some unusual programming challenges during the two-month project, – BSL completed the works safely and on-schedule, allowing the remaining construction works to begin successfully and as planned, in a dry riverside underground environment.”

Email: fiona@manifestcomms.co.uk