Talybont Reservoir Spillway, Brecon Beacons – UK

Project Overview

Constructed between 1932 and 1939 from locally quarried stone, the retaining wall along the spillway at Talybont Reservoir had experienced movement, requiring remediation to prevent further sliding. The wall stood at 2m high, with an 11m stretch requiring anchoring. Being a listed wall in a National Trust Area, a sympathetic finish was required as to not affect the aesthetic appearance of the wall.

Solution

Installation training took place on-site during the suitability testing stage. A total of 21 Platipus Stealth Anchors were driven by tracked excavator through the 127mm core holes at 1m horizontal centres. The upper row of anchors were driven to 5m from the wall face at 20° below horizontal, and the lower row to 4.5m at 5° below horizontal. The anchors were then loadlocked at a working load of 9kN. This design allowed adjustment of the core holes and anchor positions to ensure even coverage while avoiding clashes with the spillway invert by installation machinery. The anchor specification provided a permanent 120-year design life solution, while using an inverted pattress plate minimised projection from the wall, providing an aesthetic finish in keeping with the wall’s heritage, whilst accommodating the varying angles of installation.