Results
Successful strengthening of the spillway wing walls to modern seismic performance standards.
Restricted access construction challenges overcome with helicopter placement and tailored methodologies.
Structural integrity of the dam enhanced while respecting its heritage status.
Long-term performance verified through post-installation monitoring and lift-off testing.
Project delivered safely and to best practice standards in challenging environmental conditions.
Project
Solution
Installed 5 permanent 15.2mm strand anchors vertically through the wing walls into foundation rock to depths of 20m.
Anchors predrilled, pregrouted, and water-tested to confirm grout-tight conditions.
Sheathed and greased ground anchors lowered into position by helicopter due to access limitations.
Anchors tested to 880kN and locked off to design working load of 700kN.
Titan 40/16 duplex anchors installed horizontally with grout flush to provide additional seismic strengthening.
Implemented strict grout sampling and testing procedures, ensuring curing integrity in freezing temperatures.
Conducted long-term lift-off tests 12 months after installation to confirm no anchor creep.
Project
Challenges
Strengthening 1930s-era concrete wing walls on a heritage-listed dam.
Restricted access around the spillway required helicopter lifting for anchor placement.
Harsh winter conditions with sub-zero temperatures threatened grout curing and testing integrity.
Need to meet modern design life and seismic performance requirements while working within ageing concrete and fractured foundation rock.
Project
Overview
Lake Waitaki, created by the 36m-high Waitaki Dam built between 1928 and 1934, remains an important hydroelectric asset with a 105MW power station. As part of a major upgrade to Meridian Energy’s asset portfolio, the dam’s original spillway wing walls required strengthening to modern standards.
Geovert worked closely with Damwatch engineers to develop a restricted access methodology for anchor installation, ensuring compliance with BS8081 standards while protecting the historic structure.