BAM Ritchies

Case Study: Lyn Alaw Ground Anchors

Client: Dwr Cymru Welsh Water

Engineer: Atkins

Main Contractor: Black & Veatch

Location: Anglesey, Wales

Date: 2012 - 2013

BAM Ritchies carried out work involving ground anchors at Lyn Alaw Dam on Anglesey. The works involved drilling and installing 42 strand anchors up to 26.5m deep through an existing concrete dam structure.

Two types of strand anchors were designed by BAM Ritchies. Nine anchors, each with nine strands and having working loads of 1,475KN, were installed in the dam spillway.

Thirty three anchors comprising five strands, each having a working load of 700KN, were also installed across both the East and West walkways.

Access to the anchor locations was provided by means of a floating pontoon.

Prior to the drilling operations, 700mm diameter holes 0.5m deep were cored. These were followed by setting up the drilling rig vertically at each anchor location with both 200mm and 250mm diameter holes drilled to the design depth depending on each hole location.