Computing in Mining/Geotechnical Engineering ... - InfoMine

Computing in Mining/Geotechnical Engineering By: Saeed Otufat-Shamsi

The enormous advances in computational hardware and software resources over the last 15 years resulted in the development, of new, nonconventional data-processing and simulation methods. Among these methods soft computing has to be mentioned as one of the most eminent approaches to the so-called intelligent methods of information processing that present a great potential for geotechnical engineering in mining sector applications. Following are perspectives on two different areas that software applications can assist geotechnical engineers in mining sector to create, store, analyze, and disseminate raw data and processed information.

Interactive web-based visualisation of block model data By: Tony Gill, Con Caris , and Dr Guy LeBlanc Smith

Mining operations have traditionally used specialised software packages to process and visualise valuable mining data. The downside to this approach is that the information can only be viewed when the expert who knows how to operate the software is available. Today’s mining companies can spend millions of dollars to acquire data describing the spatial distribution of natural resources. Traditionally, this valuable information has been modelled by a few people trained in the use of specialised mining software packages. As a result, important information is not always readily accessible to people at the mine site and head office. CSIRO’s Virtual Mine has been built upon an existing, easy to use, interactive intranetbased visualisation system that integrates geological, geophysical, geotechnical and mining information. This system facilitates the communication between groups by making the information accessible to all within an organisation. Virtual Mine integrates three-dimensional spatial information about a mine site, generated from a variety of sources including mine modelling packages, into a single environment. The Internetbased nature and easy-to-use interface of Virtual Mine provides an important and simple mechanism through which valuable mining information is made available to all people within the mining organisation. As a result, communication between groups is facilitated to aid in the improved efficiency and safety of the mine. The integration of block model data into the system is challenging due to its volumetric structure. The proposed approach is to divide the model into slabs of a discrete width orthogonal to three axes. A VRML model is created for each slab and integrated into Virtual Mine using the existing architecture. The lightweight architecture of the Virtual Mine system makes it quick to initialise and the user interface makes it easy for users to load information as required. The cost of the system is kept low by building it upon

freely available Internet technologies. The major cost is in acquiring the expertise to build the VRML models from the raw data. One drawback of Virtual Mine is that it requires highly skilled people to build the systems and the VRML models that go in them. Efforts are being made to overcome this problem by developing an architecture that allows the GUI components of the system to be built at run-time based on data read from initialisation files at start-up. Software will then be written that allows the end user to construct the Virtual Mine systems by outputting these initialisation files based on which models the user wants in the system. Whilst this approach makes the Virtual Mine systems easy to construct, it does not solve the problem of needing highly skilled people to build the VRML models that will go into the system. One solution is to encourage suitable contractors to undertake this service. As a result of the success of implementing the block model into the existing Virtual Mine architecture, future work has been planned to improve on the model. The main area of improvement is a mechanism through which the user can view the block model in greater detail than the current 50m slabs. The first approach is to simply reduce the slab widths in the pre-processing stage. However this will result in tens of thousands of VRML files being added to the database, the majority of which may never be viewed. A second approach is to develop an architecture that permits the dynamic generation of VRML files based on user requests. Finally, a third approach is to utilise advances in graphics hardware and use a texture-based volumetric visualisation approach.

Mine Modeling – St Barbara Case Study By: Michael Forrest

Melbourne-based St Barbara Ltd selected Gemcom's Surpac resource modelling and mine design and MineSched scheduling software to provide a framework within which the 'where, when and what to mine' can be systematically answered. The packages are fully integrated. The complexity of sequencing production stopes and associated development for high grade reserves over the long life of the site requires ore grades, dilution, mining recovery, ventilation, and geotechnical parameters to be taken into account. The planning software allowed St Barbara to model all mining activities for a decade. In addition to proper scheduling, it is also necessary to validate the tonnage and grade associated with each stoping block. In the case of this mine, it is desirable to dilute and recover the stoping ore by differing percentages according to its location within the ore body. Planning engineers must therefore ensure correct application of dilution and recovery parameters and accurately account for development tonnes and grade.

Surpac software can handle the complexity of over 500 stopes, along with associated developments, and enables a graphical review of the final schedule. With Gemcom's MineSched, engineers can create underground mine schedules and view them with 3D animations. The schedule is an asset for sites such as Gwalia because it is important to maintain a particular stoping sequence with the advancing face. MineSched's graphical interface illustrates blocks of development and production so that it is obvious if errors have been made. The program enables the creation of a robust life-of-mine plan. Although the package has transformed mine scheduling, the application of dilution and mining recovery parameters can still be quite onerous. At St Barbara's request, Gemcom tailored a stoping block dilution. This extracts information from the Surpac block model for each stoping block and applies user-defined dilution parameters. The data for the diluted stoping blocks is then scheduled. The mining recovery parameter is applied within MineSched. In manual scheduling, it is time consuming to validate the practicality of various sequences. In contrast, MineSched enables personnel to repeatedly explore alternative scenarios for life-of-mine planning. Using a simple setup for short- and long-term schedules, mining engineers can simulate various activities, including dropping stopes, changing recoveries and altering pillars. There are also peripheral advantages in planning ahead, such as the ability to optimise resources and allocate capital expenditure, and all employees can see the plan as it evolves.