AMC presents paper at Underground Operators Conference 2021

AMC Consultants is proud to contribute to the Underground Operators Conference 2021 with a technical presentation. The conference is organized by the AusIMM‘ and will take place in Perth and online 15-17 March 2021.

AMC’s Ruth Stephenson (Director/Geotechnical Manager, Perth) and Mike Sandy (Principal Geotechnical Engineer, Practice Leader – Geotechnical) will present the paper “Considerations for the design and support of underground portals” in the afternoon of Day 2 of the conference.
The conference brings together suppliers, engineers and operators from the underground mining industry both from locally and internationally to share their stories of both success and challenges at their operations.

PRESENTATION: Considerations for the design and support of underground portals

SESSION 8: Innovative mining methods and practices IV

Time: 3:40-5:15 PM
Date: Tuesday 16 March 2021
Venue: Riverside Theatre


Portals to access underground mines are important infrastructure and their design requires careful consideration. Portals are generally expected to last for the life of the mine.Typically, the exposure of personnel and equipment is high, with many hundreds of movements through the portal per day. Consequently, the hazard associated with geotechnical instability must be extremely low.

Portals are often established from a boxcut. In areas where the weathering profile is well developed, the design and execution of the boxcut can involve significant effort, with the objective of minimizing the volume of the boxcut, whilst ensuring that conditions at the design depth are suitable for establishing a stable portal. Properly designed site investigations are a critical part of this process.

Currently available portal design guidelines have not been updated for decades, however the equipment and ground support systems have changed significantly in recent years. Many mine portals have since been constructed in a relatively short time frame with success, often in challenging ground conditions using some of the more modern approaches to ground support. This is beneficial because delays in establishing a portal will generally delay other critical path activities, and lead to cost overruns.


RAFFLE: Private executive summary presentation of strategy optimization

We invite delegates to visit us at booth 97 to enter our raffle. The winning prize will be a rare two-hour executive summary presentation on strategy optimization with AMC’s Brian Hall, the creator of the Hill of Value process. The private presentation and subsequent Q&A session will be for up to ten members of the winning company’s management team and will include ten digital copies of Brian’s seminal work “Cut-off Grades and Optimising the Strategic Mine Plan” published by the AusIMM.

Brian Hall

Principal Mining Engineer

Brian Hall is an internationally recognized leader in optimization of mine plans and strategies for underground and surface mines. With almost five decades of experience in the mining industry, he is a sought-after advisor and speaker on the topic.

Since coining the term Hill of Value 20 years ago, Brian has specialized in the optimization of cut-off grades and strategic mine plans. He presents workshops on project evaluation, the theory and practical application of cut-off grades, and mine and business strategy optimization. He authored the authoritative textbook, Cut-off Grades and Optimising the Strategic Mine Plan, published by the AusIMM in 2014.

Brian is also a sessional lecturer at Curtin University in Perth, where he presents a unit in the Master of Mineral and Energy Economics programme at the Curtin Graduate School of Business three times a year.

About the presenters:

Ruth Stephenson

Director/Geotechnical Manager, Perth

Ruth is a geotechnical engineer more than 17 years of experience in geotechnical engineering. Ruth joined AMC eight years ago following nine years of practical experience across several operations in Western Australia, predominantly at underground sub-level open stoping operations.

As a consultant she has provided technical and operational geotechnical support to projects and operations globally. She has a strong focus on the management of geotechnical risk from an operational perspective. With more than seven years of experience conducting underground and open pit geotechnical studies, she also has a strong focus on the potential impacts of geotechnical risk to a project.

Since joining AMC in August 2012 Ruth has worked on raise bore assessments, geotechnical reviews, and feasibility studies for underground and open-pit operations in Australia, Russia, Italy, Canada, Tanzania, Ghana, Eritrea, Indonesia, Fiji, Philippines, New Zealand and Argentina. She has provided geotechnical training to operations in Australia and Tanzania with a strong focus on geotechnical risk management. In December 2017, Ruth was promoted to Geotechnical Manager at AMC’s office in Perth.

Mike Sandy

Principal Geotechnical Engineer, Practice Leader – Geotechnical

Mike is a geotechnical engineer with more than 40 years of mining industry experience. His primary expertise is in rock mechanics (underground operations) including ground support design, rock mass characterization, mining method selection and optimization, extraction sequencing and applied numerical modelling.

Mike also has extensive experience in underground mine planning and feasibility studies, mine geology, dewatering, diamond drilling strategies and management of mining technical research.

Mike has travelled extensively in his career, including for reviews of mining projects in Canada, Ireland, Sweden, Chile, China, Indonesia, the Philippines, Turkey, South Africa, Zambia, Tanzania, Mauritania, Ghana, Russia, and the USA. He has conducted rock mechanics and mine design reviews of several large-scale open stoping operations – for example, Olympic Dam, Mt Isa – 3500 Orebody and George Fisher, St Ives Gold Mines and Mindola. Caving studies have included Big Bell (SLC), SOB Synclinorium Nkana (Mopani, SLC), Northparkes – Lift 2 (block caving), Argyle Mudrush Potential (BC and SLC), Didipio (BC/SLC), Akwaaba (SLC) and Afton (BC). High level reviews have been conducted of Bingham Canyon (BC), Resolution (BC), Oyu Tolgoi and Grasberg Block Cave.

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