Papers & Presentations

Index of available downloads

Qualification of Dynamic Ground Support

Adrian Berghorst
Symposium: Caving 2018, Vancouver, Canada
Author: Adrian Berghorst (Canada) and
Date: October 2018

Overview:
A workshop presentation on current and future trends in qualifying dynamic ground support for underground mines. There are several facilities available to the mining industry when it comes to the qualification of ground support for dynamic environments in today’s underground environment. However are these sufficient, and what is the future of ground support qualification for this essential aspect of mining in the modern world.

Download Presentation (PDF) – 354.6 MB

Caving 2018 Presentation

An Empirical Comparison between New and Existing Laboratory-based Dynamic Sample Configurations

Greig Knox
Adrian Berghorst
Pieter de Bruin
Symposium: Caving 2018, Vancouver, Canada
Authors: Greig Knox (South Africa), Adrian Berghorst (Canada) and Pieter de Bruin (South Africa)
Date: 17 October 2018

Overview:
Laboratory-based dynamic testing allows rockbolt developers to apply impulses of energy to a rockbolt in order to approximate some loading aspects that the rockbolt would experience during a rockburst in an underground mine. This data can be used to compare a rockbolt’s dynamic performance providing geotechnical engineers with useful information for designing their required ground support system. There are two general sample configurations commonly used in this type of dynamic testing – split-tube test and continuous-tube test. This paper summarises a proposed a third configuration – a multi-split-tube test.

Download Paper (PDF) – 1.8MB

Download Presentation (PDF) – 21.8MB

Caving 2018 Presentation

A New Dynamic Test Facility for Support Tendons

Brendan Crompton
Adrian Berghorst
Greig Knox
Publication: Australian Centre for Geomechanics Newsletter
Authors: Brendan Crompton (Australia), Adrian Berghorst (Canada) and Greig Knox (South Africa)
Date: August 2018

Overview:
Given the increasing need and benefit in better understanding and designing dynamic support elements, New Concept Mining built a new dynamic test machine, the Dynamic Impact Tester (DIT), at their research facility in Johannesburg, South Africa.

Download Article (PDF) – 411kB

ACG Newsletter August 2018

Dynamic Testing of Ground Support

Brendan Crompton
Author: Brendan Crompton – BSc (Eng) (Mechanical), MBA
Date: 24 July 2018

Overview:
This presentation considers the differences in performance of ground support under quasi-static and dynamic loading and the various types of dynamic testing currently available to the mining industry. Specific focus is given to the methodology and results achieved from the dynamic laboratory testing of rockbolts as well as the presentation and interpretation of test results. A practical approach to better utilise laboratory results for the monitoring of support performance underground is also proposed.

Download Presentation (PDF) – 207MB

Dynamic Impact Test

Relationship Between Energy Per Impulse and Dynamic Capacity of a Rockbolt

Koos Bosman
Martin Cawood
Adrian Berghorst
Authors: Koos Bosman (Open House Management Solutions), Martin Cawood (NCM South Africa), Adrian Berghorst (NCM Canada)
Date: 2018

Overview:
The capacity of a rockbolt subjected to an impulse of energy varies as a function of the magnitude of the impulse of energy applied. This paper explores the relationship between the magnitude of the impulse of energy applied to a rockbolt and the resulting dynamic capacity. The result of this research shows that for a given velocity at impact, there is a linear relationship between the magnitude of the individual impulses of energy applied to a rockbolt and the resulting dynamic capacity of the rockbolt. The dynamic capacity of a rockbolt is not a constant value. During this research, the relationship between the magnitude of the impulse and the resulting displacement of the rockbolt is also examined.

Download Paper (PDF) – 335kB

Download Presentation (PDF) – 37MB

Energy & Dynamic Capacity Paper

Increased Agility for the Research & Development of Dynamic Roof Support Products

Greig Knox
Adrian Berghorst
Conference: RocDyn-3, Trondheim, Norway
Authors: Greig Knox (NCM South Africa), Adrian Berghorst (NCM Canada)
Date: 26 June 2018

Overview:
New Concept Mining (NCM) has developed the Dynamic Impact Tester (DIT) capable of testing as many as 179 rock bolts in a period of six months, with no interruptions to mining operations. The limitations of the dynamic axial loading testing method are known, however, the DIT provides an efficient platform, on which a large number of tendon support systems can be compared under controlled conditions with increased agility. During the rapid development of new rock bolt products it is crucial to quantify the effects of high strain rates exerted by rock bursts on ground support systems. The DIT provides this capacity.

Download Paper (PDF) – 3.2MB

Download Presentation (PDF) – 37MB

RocDyn-3 Paper

The Development of a Multi-Split-Tube Sample Configuration

Greig Knox
Adrian Berghorst
Authors: Greig Knox (NCM South Africa), Adrian Berghorst (NCM Canada)
Date: 2018

Overview:
The introduction of a new testing configuration, whereby a split is introduced between each anchor pair along the entire rock bolt and the loading is applied to the washer. The purpose of the Multiple Split Tube test is to attempt to more accurately simulate the expected loading of the complete length of rock bolt in highly fractured ground. Since this new testing configuration loads the entire length of the bolt, an increase in the ultimate absorbed energy and deformation have been noted when compared to traditional split tube tests.

Download Presentation (PDF) – 2.1MB

Multi-Split-Tube Paper