Geotechnical

In line with Australia’s commitment to reduce carbon emissions and move towards renewable energy, Snowy 2.0 is a major project estimated to cost in the region of A$5.2 billion. Early feasibility studies investigated the viability of a tunnel linking Lake Talbingo and Lake Tantangara. Situated underground, along the tunnel would be the power station housing six turbines capable of generating 2000 megawatts. Power generation is not expected until 2025. The initial site investigation by SMEC and GHD led to HMA Geotechnical being awarded the instrumentation installation work. HMA Geotechnical began installation work in November 2017 and completed the work in February 2021

Construction of Keepit Dam began in the late 1930’s but was delayed during WW2. Work was restarted after the war and only reached completion in 1960. The mass concrete main dam and several rock-filled saddle dams give a storage capacity of 425000 megalitres. Keepit Dam has undergone recent upgrades, the most recent was to strengthen the concrete structure using post tensioned cables. This work would ensure potential overturning effects during flood and/or earthquake events would be mitigated HMA Geotechnical was contracted to supply large diameter Vibrating Wire load cells and logging systems to monitor the tensioning of the reinforcing cables and thereby the load in kN.

To relieve traffic pressure on the existing Harbour Bridge and Tunnel, the NSW Government sought expressions of interest to build a second tunnel to the Western side of the harbour in July 2020. In June 2021, NSW 2021-2022 budget allocated $6.3 billion over the next four years for the Western Harbor link to go ahead. In Dec 2021the geotechnical investigation was awarded to GHD and SMEC. HMA Geotechnical was selected to provide the instruments and installation equipment for boreholes in nine locations. Site work commenced mid-February 2022

At 287 giga litres Cardinia Reservoir is Melbourne Water’s second largest reservoir. Constructed in the early 1970’s it has no direct catchment, instead water is fed via Silvan Reservoir and more recently the Victorian Desalination Plant. With recent improvements in dam safety and design standards Cardinia Dam has slipped below best practice guidelines in dam safety. The upgrade to Cardinia dam will bring the fifty-year-old structure back into compliance with the guidelines issued by the Australian National Committee on Large Dams. (ANCOLD) Melbourne Water has a duty of care to comply under the Water Act 1989 for all dams within its portfolio. The upgrade works are due to start in 2024/25 and expected completion is mid 2025

Located in the Latrobe Valley, Victoria, Australia. Hazelwood Power station was constructed during the mid to late 1960’s and supplied Victoria with up to 25% of its power. The brown coal fuel for the eight 200MW turbines was mined from the adjoining pit. In 2005 the World Wildlife Fund reported that Hazelwood power station was one of the world’s most polluting, emitting 3% of Australia’s annual greenhouse gas emissions. In 2016, Engie, the joint owner, announced the power station and mine would close and in March 2017 it finally closed. The power station was demolished in November 2020. The 1,281hectare mine presented another problem. The plan is to allow the void to fill with

Constructed in 1957 Upper Yarra dam is located 23km Northeast of Warburton, Victoria. In 2017 Melbourne Water announced that upgrades of the dam wall and surrounds were necessary. In 2019 the first stage of upgrades began with the second stage commencing in 2020. HMA Geotechnical became involved with the upgrades mostly through improved logging equipment, Instrument cable extensions and Weir monitor calibrations. Re-routing instrument cables and preserving them during construction was a major undertaking.

Grange Resources operates Savage River Mine which lies 100km Southwest of Burnie in Tasmania. The magnetite ore body stretches 25km south of the Savage River township ranging in thickness from 40m to 150m. Current production is two million tonnes of premium iron ore pellets; this is expected to rise to nearly three million tonnes as the open cut mine extends underground. HMA Geotechnical was contracted to install vibrating wire piezometers both in the open cut pit and the newly opened underground drive.