Bray Head Hotel

Quinn Piling was appointed by DNCF to design and construct an innovative piled retaining wall solution as part of the redevelopment of the former Bray Head Hotel in Co. Wicklow.

The iconic hotel building, a protected structure overlooking Bray seafront, was converted into a series of luxury apartments. To facilitate the construction of a new rear structure and associated parking facilities, a substantial retaining wall was required adjacent to the Iarnród Éireann railway line, which sits approximately 10 metres above the development level.

Due to the close proximity of the railway infrastructure, a conventional anchoring solution was not feasible as ground anchors would have extended beneath the railway boundary. Quinn Piling developed an innovative solution incorporating raked rotary bored anchor piles integrated into the secant piled wall system, ensuring lateral wall movements remained within the project specification while eliminating any impact on the adjacent railway corridor.

In total, over 50 linear metres of secant piled wall were constructed with retained heights of up to 9 metres, together with a 10 metre long king post wall section to accommodate neighbouring boundary constraints.

Piling Scope & Details

The retaining structure comprised:

• 27 No. 1,040mm diameter hard secant piles installed to depths of 13–18m.
• 29 No. 740mm diameter firm secant piles installed to depths of 13–18m.
• 12 No. 940mm diameter raked anchor piles installed to depths of 10–15m.
• 6 No. king posts installed within 740mm diameter bores.
• All piles constructed using rotary bored techniques with temporary casing support.

Ground Conditions

Ground conditions encountered across the site consisted of up to 2 metres of made ground overlying stiff to very stiff clay deposits extending to approximately 5 metres depth.

Dense sands and gravels were encountered beneath the clay strata, with perched groundwater present within the granular layers. The prevailing groundwater level remained below the final excavation depth throughout the works.

Challenges

The primary challenge on the project was the requirement to construct a deep retaining structure immediately adjacent to an operational railway line while maintaining strict movement tolerances.

Traditional ground anchors were not a viable option due to the potential encroachment beneath railway lands. Quinn Piling therefore designed and installed a system of raked rotary bored anchor piles integrated into the secant wall, providing the required restraint without extending beyond the site boundary.

The project also required careful coordination around the existing protected structure, restricted working areas and varying boundary conditions, including the construction of a king post wall section connected to the secant wall system.

Outcome

The completed retaining wall provided a robust and innovative solution that enabled the successful redevelopment of the former Bray Head Hotel while protecting both the adjacent railway infrastructure and the existing protected structure.

The project demonstrated Quinn Piling’s ability to develop bespoke foundation and retaining wall solutions in technically challenging environments where conventional construction methods are not suitable.